Microfluidic device, protein defect diagnostic device with microfluidic device, method for protein defect diagnosis and method for analyzing protein defects

Abstract

A microfluidic device (12) for applying blood samples to a sensor element (26) for protein defect diagnosis and / or for conditioning a sensor element (26) for protein defect diagnosis is proposed, as is a protein defect diagnosis device (10) with the microfluidic device (12). A method for applying blood samples to a sensor element (26) for protein defect diagnosis and / or for conditioning a sensor element (26) for protein defect diagnosis and a method for analyzing protein defects in a blood sample (212) are also disclosed.

Description

[0001] The invention relates to a microfluidic device for applying a blood sample to a sensor element for a protein defect diagnosis and / or for conditioning a sensor element for a protein defect diagnosis, a protein defect diagnosis device comprising the microfluidic device, a method for applying a blood sample to a sensor element or for conditioning a sensor element for protein defect diagnosis, and a method for analyzing protein defects.

[0002] Alzheimer's disease, or Alzheimer's disease (hereafter referred to as Alzheimer's), is a currently incurable, neurodegenerative disease in which nerve cells in the brain steadily die, leading to personality and behavioral changes in those affected as the disease progresses. Millions of people worldwide are affected by Alzheimer's disease.

[0003] An early diagnosis of Alzheimer's is particularly important for the course of the disease, as although Alzheimer's is not yet curable, its steady progression can be slowed with early treatment. The earlier treatment is started, the more beneficial it is. Early and reliable diagnosis therefore represents a key challenge in diagnostic medical technology, enabling timely intervention and slowing of the disease's progression. Prediagnostic methods play a special role in this regard, as they allow for advance predictions regarding the risk of a clinical Alzheimer's diagnosis and therapeutic measures to be initiated even before the clinical onset of symptoms of the disease.

[0004] Known prediagnostic methods for predicting Alzheimer's risk rely on the analysis of specific protein defects that develop in the human body decades before the clinical onset of Alzheimer's. The analysis of such protein defects enables predictions about the likelihood of developing Alzheimer's. From a scientific perspective, it is assumed that misfolding of certain proteins, such as β-amyloid (Aβ) peptides, occurs in the early stages of Alzheimer's. According to current research, the misfolding and resulting aggregation of the peptides into beta-sheet-enriched amyloid plaques is crucial for the course and progression of Alzheimer's.

[0005] For this reason, the presence of misfolded β-amyloid (Aβ) peptides, for example, in the blood plasma of test subjects, is a sign of possible Alzheimer's disease and can be an important indicator for Alzheimer's risk prognosis. Thus, the misfolded β-amyloid (Aβ) peptide represents a candidate biomarker peptide that can be used in prediagnostic methods.

[0006] In the field of protein diagnostics, there are a number of methods for detecting candidate biomarker peptides in samples. For example, methods such as enzyme-linked immunosorbent assays (ELISA), surface plasmon resonance spectroscopy (SPR), or surface-based fluorescence intensity distribution analysis (sFIDA) can be used for this purpose. However, it has been shown that these methods only provide indirect information about structural defects or misfolding of proteins. Furthermore, these methods are very complex in sample preparation and implementation and are designed for low sample throughput, making them unsuitable for large-scale clinical applications.

[0007] Another method in the field of protein diagnostics is the immuno-infrared sensor assay (hereinafter referred to as immunoassay), which allows for the direct measurement of misfolded β-amyloid (Aβ) peptides in body fluids such as blood, blood plasma, blood serum or cerebrospinal fluid without prior isolation and preparation of candidate biomarker peptides.

[0008] Such an immunoassay is disclosed, for example, in US 2020 / 0 141 866 A1. The immunoassay described focuses specifically on protein diagnostics of misfolded amyloid-β (Aβ) peptides for Alzheimer's disease risk prediction. The basic principle of the method is to bind an antibody to a sensor surface-modified with silanes or thiol linkers, which in turn can specifically bind candidate biomarker peptides based on (Aβ) structures.

[0009] For this purpose, in a first preconditioning step, a sensor crystal, for example an ATR (attenuated total reflection) sensor crystal such as a germanium or silicon single crystal, is surface-treated with the conditioning fluids containing silane or thiol linkers. In a second antibody conditioning step, the sensor surface is surface-treated with an antibody-containing conditioning fluid. In a third sample application step, the sensor is then surface-treated with a sample fluid from a test subject, for example, blood plasma, blood, or blood serum, whereby candidate biomarker peptides based on (Aβ) structures bind to the antibody-coated sensor surface.In a fourth step, the measurement step, this is irradiated with an IR laser, which passes through the sensor through multiple internal total reaction, recording an IR spectrum of the candidate biomarker peptides based on (Aβ) structures bound to the sensor element surface. The IR spectrum recorded by the bound candidate biomarkers is then evaluated, for example, by quantifying the shift of the IR bands of the candidate biomarker peptides based on (Aβ) structures using comparative measurements, in order to make a risk prediction regarding the possible onset of Alzheimer's disease in the sample under investigation.

[0010] However, such immunoassays for Alzheimer's risk prediction are in an early phase of development and have so far only been conducted on a laboratory scale and as proof-of-concept trials. In particular, the development of such an immunoassay away from the laboratory scale and toward industrial, large-scale medical application represents an immense challenge.

[0011] In known immunoassays, individual devices are used to carry out the above-mentioned steps, which have a number of disadvantages, which are discussed below.

[0012] Common immunoassays are typically based on a flow cell with a fluid port at each of its opposite ends. Both fluid ports are fluidically connected to a common reservoir, so that the sample to be analyzed is pumped along a circuit between the flow cell and the reservoir via a peristaltic pump.

[0013] However, flow cells are costly and require complex preparation. Therefore, time-efficient throughput of larger sample volumes is not possible, and analysis is limited to individual samples.

[0014] The use of a peristaltic pump also increases the risk of sample fluid contamination. To avoid this, it is necessary to regularly clean the peristaltic pump, for example, by autoclaving it, to prevent cross-contamination between different sample fluids.

[0015] Furthermore, the manual assembly and disassembly of the experimental setup between measurements complicates the reproducibility of the immunoassay and thus efficient sample throughput.

[0016] Furthermore, the conditioning of the sensor surface and the subsequent sample application with the sample fluid do not take place in the same flow cell, so multiple specialized devices are used for sample preparation and measurement. This procedure, in turn, is time-consuming and increases the risk of sample fluid contamination, as the sensor is passed back and forth between devices for conditioning and sample application.

[0017] Parkinson's disease and amyotrophic lateral sclerosis (ALS) should also be able to be predicted early on by analyzing specific protein defects in the blood. The invention is therefore intended to encompass, among other things, a device and a method for conditioning sensor elements and analyzing protein defects using the sensor elements for these diseases, ie, more generally, for preparing and performing an analysis of protein defects.

[0018] In this respect, the object of the present invention is to remedy at least one disadvantage known from the prior art.

[0019] The object is achieved according to the invention by a microfluidic device for applying a blood sample to a sensor element for a protein defect diagnosis and / or for conditioning a sensor element for a protein defect diagnosis according to claim 1.

[0020] Advantageous aspects of the invention emerge from the subclaims, which can optionally be combined with one another.

[0021] According to the invention, the microfluidic device comprises at least one interaction chamber, which is partially closed by a sensor element, wherein a first fluid channel opens at one end of the at least one interaction chamber and a second fluid channel opens at the opposite end. Furthermore, the microfluidic device comprises a first media dosing unit for conditioning fluid, which is selectively fluidically connected to the first fluid channel at one end of the at least one interaction chamber via at least one valve, and a second media dosing unit for conditioning fluid, which is selectively fluidically connected to the second fluid channel at an opposite end of the at least one interaction chamber via at least one valve.Alternatively or in addition to the first and second media dosing units, the device has at least one first blood sample receptacle, which transitions into a first sample channel and an associated first fluid channel, and at least one second blood sample receptacle, which transitions into a second sample channel and the associated second fluid channel, such that each interaction chamber is fluidly connectable only to its own first and second blood sample receptacles. Furthermore, the microfluidic device comprises a pneumatic unit connected to the first and second media dosing units and / or the first and second blood sample receptacles and configured to alternately apply positive pressure and negative pressure or positive pressure and ambient pressure to them and to pump conditioning fluid and / or the blood sample back and forth through the at least one interaction chamber.

[0022] The invention is based on the fundamental idea of ​​providing a central interaction chamber into which a surface of a sensor element to be treated can be introduced, in order to alternately expose it to a conditioning fluid from the media dosing units, which flows into the interaction chamber either from the first or from the second media dosing unit. With the incoming conditioning fluid, the surface of the sensor element can be surface-treated, i.e., conditioned, and prepared for the subsequent application of a blood sample.In this sense, the central arrangement of the interaction chamber between two media dosing units enables particularly efficient fluid flow through the interaction chamber, because the respective medium from the first or second media dosing unit completely traverses this interaction chamber along its longitudinal direction upon entering the interaction chamber, thus ensuring uniform contact with the sensor element surface before the medium exits the interaction chamber again. The same applies to the back-and-forth pumping of a blood sample between blood sample intakes.

[0023] Simply put, the above arrangement enables bidirectional fluid flow from one media dosing unit to the other media dosing unit and back again, or between blood sample intakes. This allows a small volume of conditioning fluid or blood sample to efficiently condition a large area of ​​the sensor element or allow it to come into contact with a blood sample for analysis. Furthermore, the process—conditioning the surface with the flowing conditioning fluid or analyzing the blood sample to detect a protein defect—is also accelerated.

[0024] The use of a pneumatic unit is particularly advantageous because the conditioning fluid to be moved can be pumped contactlessly from one media dosing unit via the interaction chamber to the other media dosing unit or the blood sample can be pumped back and forth from one blood sample receptacle to the other.

[0025] Furthermore, the valves arranged along the fluid channels allow precise control of the fluid flow.

[0026] The term "interaction chamber" refers to a chamber in which at least one fluid flowing through the fluid channels can be brought into contact with the sensor element in order to interact with the surface of the sensor element. The term "chamber" is not to be interpreted in a restrictive manner; it can also refer to a chamber section, a channel, or a channel section that is open and engageable with a sensor element. In this respect, at least the surface treatment, i.e., the conditioning of the sensor element surface with a linker-containing or antibody-containing conditioning fluid, takes place in the interaction chamber. Depending on the embodiments explained below, in addition to the conditioning, the sample application with a sample fluid to the conditioned surface can be carried out in the interaction chamber, alternatively or additionally, as well as the measurement process on the sensor element surface.

[0027] In principle, the interaction chamber can have any shape and geometry. However, it is preferred that the interaction chamber has a larger cross-section, at least in one direction, compared to the other channels in the disposable fluid guide assembly, in order to slow the fluid flow and allow the fluid to interact with the sensor element for a longer time.

[0028] A “sensor element” refers to any sensor element suitable for protein diagnostics using FTIR spectroscopy.

[0029] A "channel" or "fluid channel" refers to a tubular connection designed to carry a fluid. The term "channel" or "fluid channel" can also refer to a channel section.

[0030] The terms “fluidic” and “fluid” used in this application refer exclusively to liquids.

[0031] The term “reversibly connectable” means that the disposable fluid guide assembly is designed to be non-destructively connected, i.e. coupled, to the individual components of the microfluidic device and then separated, i.e. decoupled.

[0032] According to a first aspect of the invention, a detection unit is provided which monitors the fluid flow in a contactless manner adjacent to the ends of the interaction chamber.

[0033] This makes it possible to determine which section of the fluid channels the fluid flow is located in, allowing precise control of the fluid flow. This is particularly important for small volumes, as the conditioning fluid / blood sample is not necessarily conveyed as a continuous fluid flow from the first media dosing unit via the interaction chamber to the second media dosing unit or between the blood sample receptacles. Instead, a discrete fluid flow, i.e., with a recognizable beginning and end, is often pumped back and forth between the media dosing units / blood sample receptacles. Determining the position of this discrete fluid flow is particularly easy using the detection unit and allows precise control of the valves.

[0034] In a particularly advantageous embodiment of the invention, it is provided that the detection unit is designed such that it detects the occurrence of air bubbles in a fluid channel, and wherein a control is provided which brings about a flow reversal when an air bubble occurs.

[0035] When pumping discrete fluid streams back and forth, an air front in the form of air bubbles is arranged before and after the discrete fluid stream of medium, which moves back and forth with the discrete volume between the media dosing units / blood sample receptacles. By detecting such air bubbles, or more precisely by detecting the transition from air bubble to fluid stream, the beginning or end of the discrete fluid stream can be precisely determined. This can be recorded by the detection unit, which can send a signal to the controller, which then initiates a flow reversal of the fluid stream. This allows the time for the flow reversal to be determined metrologically without having to resort to estimates that are often less accurate and cannot react to process fluctuations. Furthermore, it can be ensured that the sensor element is always covered with liquid.

[0036] A further aspect of the invention provides that a disposable fluid guide assembly is provided which has the interaction chamber, the fluid channels or sections of the fluid channels and valves and to which the sensor element is attached and to which the media dosing units can be reversibly coupled and / or into which one or more blood samples can be fluidically introduced, in particular wherein the disposable fluid guide assembly has sensor windows which lead adjacent to the opposite ends up close to the fluid channels and via which the detection device is visually coupled to the interior of the fluid channels.

[0037] The disposable fluid guide assembly with an integrated interaction chamber, fluid channels or sections of the fluid channels, and valves offers the advantage of easily preventing contamination between different fluids. The "used" disposable fluid guide assembly can be disposed of after conditioning / blood analysis and replaced with a "fresh" disposable fluid guide assembly. This eliminates the need for time-consuming cleaning of the fluid-carrying channels and the associated valves.

[0038] The sensor windows provide a clear view of the fluid channels leading to and from the interaction chamber, allowing fluid flow within these channels to be optically monitored. For example, bubbles or a gas or fluid front can be detected via the sensor windows. In principle, the sensor windows can have any geometry as long as they allow a fluid flow within the fluid channels to be visible to the outside. Therefore, the term "close" means that, depending on the optical density of the disposable fluid guide assembly, the sensor windows extend to the fluid channels until they are optically accessible to a sensor system.

[0039] The design of the sensor windows, directly adjacent to the fluid channels in the interaction chamber, enables particularly early detection of air bubbles, which also allows for a particularly timely flow reversal. This avoids dead time during which the interaction chamber is not in contact with the medium.

[0040] The disposable fluid guide assembly can have a lower part with a fluid side and an opposite lower side, and an upper part with an upper side and an opposite pneumatic side adjacent to the fluid side of the lower part. The upper part on the pneumatic side and the lower part on the fluid side each have a plurality of channels formed by grooves. Furthermore, the disposable fluid guide assembly provides at least one sealing element that fluidically separates pneumatic channels in the upper part, arranged opposite one another between the fluid side and the pneumatic side, from fluid channels in the lower part. At least one interaction chamber open to the lower side is formed in the lower part and can be closed by a sensor element attachable to the lower side and preferably flush with the lower side.Diaphragm valves are formed between the pneumatic side and the fluid side by means of one or more sealing elements, via which fluid channels leading to and away from the interaction chamber can be opened and closed.

[0041] The fluid guide assembly is designed for single use in a microfluidic device for applying blood samples to a sensor element for protein defect diagnosis and / or for conditioning a sensor element for protein defect diagnosis. By introducing a disposable function, contamination of sample fluids with conditioning fluids or cross-contamination between different sample fluids can be easily prevented because the "used" disposable fluid guide assembly can be disposed of after each sample run and replaced with a "fresh" disposable fluid guide assembly. The same applies to blood sample application. This eliminates the time-consuming cleaning of the fluid-carrying channels and the associated valves.

[0042] Furthermore, the design with an upper part, a lower part, and an intermediate sealing element represents a particularly efficient and compact fluid guide. In this design, the sealing element provides a sealing effect between the upper and lower parts and also a control effect that allows a fluid to be switched within the fluid channels. In particular, the incorporation of diaphragm valves into the disposable fluid guide assembly shifts the complexity of the fluid guide from a microfluidic device to the disposable fluid guide assembly, thereby streamlining the periphery of the disposable fluid guide assembly. This also works synergistically with the disposable functionality of the fluid guide assembly, as the diaphragm valves contaminated with sample fluid can be disposed of after the sample fluid has passed through.This eliminates the need to clean the fluid control system, and the disposable fluid guide assembly enables higher sample throughput without time-consuming cleaning steps. The upper and lower sections can also be easily manufactured from plastic, e.g., by injection molding.

[0043] Furthermore, the design of the interaction chamber is particularly advantageous because it is constructed in such a way that it can be sealed fluid-tight from the outside by the sensor element without the need for additional components. The sensor element thus already forms a kind of lid for the interaction chamber.

[0044] The terms "top and bottom" are not to be interpreted in a restrictive sense, but merely serve to conceptually distinguish the sides and orientation of the top and bottom parts relative to each other. Preferably, the top part is inserted into a microfluidic device with its top side facing upwards. The top and bottom parts can each be formed as a single piece or assembled from multiple parts.

[0045] The term "interaction chamber" refers to a chamber in which at least one fluid flowing through the fluid channels can be brought into contact with the sensor element in order to interact with the surface of the sensor element. The term "chamber" is not to be interpreted in a restrictive manner; it can also refer to a chamber section, a channel, or a channel section that is open and can be brought into engagement with a sensor element. In this respect, at least the application of a blood sample to the surface of the sensor element takes place in the interaction chamber. Depending on the embodiments explained below, in addition to the sample application, conditioning—i.e., the surface treatment of the sensor element surface with a linker-containing or antibody-containing conditioning fluid—as well as the measurement process on the sensor element surface can be carried out in the interaction chamber.

[0046] In principle, the interaction chamber can have any shape and geometry. However, it is preferred that the interaction chamber has a larger cross-section, at least in one direction, compared to the other channels in the disposable fluid guide assembly, in order to slow the fluid flow and allow the fluid to interact with the sensor element for a longer time.

[0047] A “sensor element” refers to any sensor element suitable for protein diagnostics using FTIR spectroscopy.

[0048] A "channel" or "fluid channel" refers to a tubular connection designed to carry a fluid. The term "channel" or "fluid channel" can also refer to a channel section.

[0049] The terms “fluidic” and “fluid” used in this application refer exclusively to liquids.

[0050] According to a first aspect of the invention, it is provided that the upper part has pneumatic channels opening at the top, which end at associated diaphragm valves in order to switch them.

[0051] Pneumatic channels represent a simple design for fluidly connecting and switching the upper surface of the upper part with the diaphragm valves located inside the one-way fluid guide assembly. For example, the pneumatic channels can extend vertically and continuously through the upper part to the diaphragm. However, it is also conceivable for the pneumatic channels to have differently shaped sections that form a common pneumatic channel connecting the diaphragm valve to the upper surface of the upper part. The pneumatic channels can all have the same shape or be shaped independently of one another.

[0052] According to a further aspect of the invention, the lower part has fluid channels opening at the bottom and leading to opposite ends of the interaction chamber, which form media channels for the flow of medium for conditioning the surface.

[0053] The term “medium” refers to a conditioning fluid or a fluid that is necessary for the conditioning process, i.e. for preparing the sensor element surface for sample application.

[0054] Media channels represent a simple design for fluidically connecting the interaction chamber to the outside of the lower part. Furthermore, the opening of the media channels on the underside of the lower part ensures particularly bubble-free introduction of medium into the disposable fluid guide assembly. The occurrence of bubbles or air-fluid turbulence in the fluid channels of the disposable fluid guide assembly is undesirable, as these can lead to an irregular fluid flow and thus impair the connected sensors for monitoring the fluid flow.

[0055] Furthermore, it's easy to quickly and securely connect the external connections to the ports on the one-way fluid guide assembly, ensuring a tight seal. All pneumatic connections are located on the top and the media connections on the bottom. For example, it's possible to combine connections in blocks into one part, which is then simply clamped against the top or bottom.

[0056] By providing media channels, the disposable fluid guide assembly is designed to precondition a sensor in the interaction chamber for sample application, i.e., to condition it with at least one medium. This eliminates the need to condition the sensor element outside the disposable fluid guide assembly using a separate device. The interaction chamber thus fulfills a dual function, making the disposable fluid guide assembly particularly space-saving.

[0057] In particular, sensor windows are provided in the upper or lower part, which run adjacent to the opposite ends up close to the fluid channels.

[0058] The sensor windows provide a clear view of the fluid channels leading to and from the interaction chamber, allowing fluid flow within these channels to be optically monitored. For example, bubbles or a gas or fluid front can be detected via the sensor windows. In principle, the sensor windows can have any geometry, as long as they allow a fluid flow within the fluid channels to be visible to the outside. Therefore, the term "close" means that, depending on the optical density of the upper and lower sections, the sensor windows extend from the top and / or bottom to the fluid channels until they are optically accessible to a sensor system.

[0059] Media channels can open at the opposite ends of the interaction chamber, each leading to a media connection in an outer surface of the upper or lower part.

[0060] Due to the opposing arrangement of media channels in the interaction chamber, the chamber can be completely permeated by a medium conveyed in the media channels along a longitudinal direction. This allows a sensor element installed in the interaction chamber to be brought into particularly uniform contact with the medium conveyed in the media channels.

[0061] A further aspect of the invention provides that the upper part has at least one first blood sample receptacle on the upper side, which is fluidically connected to a fluid channel designed as a sample channel, which can be selectively connected to the interaction chamber via a diaphragm valve.

[0062] In other words, the disposable fluid guide assembly contains an integrated blood sample receptacle. This makes the blood samples to be analyzed particularly easy to handle, as they can be introduced into the disposable fluid guide assembly without the need for any additional separate device. The interaction of the blood sample with the sensor element and the necessary fluid flow are thus limited to the disposable fluid guide assembly. Accordingly, cleaning of peripheral devices is eliminated, as the disposable fluid guide assembly can be disposed of together with the blood sample receptacle after a single sample run. This ensures particularly low-contamination work.

[0063] The blood sample intake refers to a section of the disposable fluid guide assembly that acts as an inlet through which blood samples can be introduced into the sample channels so that they can pass through the fluid channels into the interaction chamber.

[0064] In particular, the blood sample holder may be in the form of a chamber or a molded container into which the blood samples can be inserted.

[0065] The term "blood sample" refers to the sample fluid of a subject to be tested for candidate biomarkers that may indicate a later diagnosis of Alzheimer's disease or another neurodegenerative disease. The blood sample can include, for example, blood plasma, cerebrospinal fluid, blood or blood serum, or, more generally, processed blood. Furthermore, the terms "blood sample" and "sample fluid" are used synonymously.

[0066] A further aspect of the invention provides that the blood sample receptacle is formed by a cavity in the upper part and an adjoining cavity in the lower part and the sample channel extends from the cavity in the lower part.

[0067] The blood sample intake design described here creates a fluidic connection from the upper part via the lower part to the interaction chamber located therein. In addition, the sample can be easily introduced into the disposable fluid guide assembly from above, i.e., viewed from the top. This particularly simplifies the handling and introduction of blood samples, as these are often still manually pipetted into the blood sample intake.

[0068] In addition, the blood sample can be introduced spatially separately from the media, which are preferably introduced into the fluid guide assembly via the underside of the lower part, thus ensuring low-contamination fluid guide and introduction.

[0069] According to a further aspect of the invention, a second blood sample receptacle is formed in the upper part, which is fluidically connected to the interaction chamber and the first blood sample receptacle via a sample channel.

[0070] This arrangement allows sample fluid to flow from the first blood sample receptacle via the first blood sample channel into the interaction chamber and then into the second sample channel into the second blood sample receptacle, and vice versa. For example, one blood sample receptacle can serve as the initial reservoir, and the other as the receiving reservoir after passing through the interaction chamber.

[0071] In particular, the second blood sample receptacle is arranged as a mirror image of the first blood sample receptacle with respect to the interaction chamber, i.e., on opposite sides of the interaction chambers. Mirror image does not mean that the distances to a fictitious mirror axis must be exactly the same, but rather that the blood sample receptacles are arranged largely symmetrically and opposite each other on opposite sides of the interaction chambers, or, in a row arrangement of interaction chambers, on opposite sides of this row.

[0072] Due to the identical design of the blood sample holders, the blood samples can be introduced into their assigned interaction chamber reproducibly and at the same flow rate.

[0073] A further aspect of the invention provides that the blood sample receptacles each have an opening for applying pressure or negative pressure or positive pressure and ambient pressure.

[0074] Advantageously, by applying pressure and negative pressure or positive pressure and ambient pressure to the blood sample receptacle, a blood sample contained therein can be pumped contactlessly from the blood sample receptacle into the interaction chamber. This provides a particularly low-contamination transport of sample fluid within the disposable fluid guide assembly. Consequently, a pressure difference must be maintained between the two ends of the interaction chamber to guide the sample through it.

[0075] This design works synergistically with the mirror-image design of the blood sample holders.

[0076] By creating a pressure difference between the mirror-image blood sample receptacles, each of which shares a fluidic connection to the interaction chamber via a sample channel, a sample fluid can be pumped back and forth between the two blood sample receptacles. This easily improves the efficiency of sample application to a sensor element coated with an antibody. The back-and-forth pumping ensures a constant fluid flow within the interaction chamber, ensuring that sample fluid is always brought into contact with the antibody-coated surface of the sensor element, significantly reducing the required blood sample volume.

[0077] A further aspect of the invention provides that the sample channel and the media channel are combined at an interface to form a common fluid channel, wherein a diaphragm valve is located at the interface, which controls the inflow of the blood sample or medium into the common fluid channel.

[0078] The shared fluid channel significantly reduces the number of channels required within the disposable fluid guide assembly, saving space and simplifying the design of the interaction chamber. The single inlet and blood sample collection outlet of the interaction chamber can also be optimally positioned.

[0079] Furthermore, the provided interface offers the possibility of controlling the flow of the blood sample from the respective sample channel and of the desired medium via the media channel into the interaction chamber. Accordingly, the interface allows for easy fluidic separation of the sample channels and the fluid channels, thus preventing mixing of the sample fluid and the conditioning fluid, as well as the flow of conditioning fluid into the blood sample receptacle.

[0080] In a further aspect of the invention, it is provided that a common fluid channel ends at the opposite ends of the interaction chamber, which then splits into a media channel and a sample channel, wherein a diaphragm valve is provided at each interface in the media channel.

[0081] The assignment of an interface with a diaphragm valve to the respective opposite ends of the interaction chamber makes it easy to control the inflow of sample fluid and medium along the fluid channels leading to and from the interaction chamber with the smallest possible number of channels and valves.

[0082] A further aspect of the invention provides that the sample channel forms a sample riser toward the interface, which is surrounded by the valve seat. The media channel splits into two subchannels and runs around opposite sides of the riser. The subchannels reunite downstream of the riser to form the interaction chamber.

[0083] This represents a particularly efficient design for fluidically separating the sample channel from the media channel. When closed, the sealing element rests on the valve seat as a diaphragm valve, whereby the riser of the sample channel is closed off by the sealing element and thus fluidically separated from the two sub-channels. Actuating the diaphragm valve at the interface causes the diaphragm to lift upwards from the valve seat towards the upper part, thereby exposing the riser, which is then fluidically connected to the two surrounding sub-channels. The valve is thus opened and a fluidic connection is established between the sample channel and the interaction chamber. Whether the valve is closed or open, the media channel, which splits into two sub-channels, remains fluidically connected to the interaction chamber.

[0084] A further aspect of the invention provides that the riser is formed by a sleeve-shaped extension which has a gusset-shaped nose on opposite sides to the respective branching point of the sub-channels, which delimits the sub-channels in sections.

[0085] The gusset-shaped contour divides and joins the media channel with minimal dead space. A contour that is as dead space-free as possible prevents fluid from remaining in a dead space at the interface when the volume is actuated, thus contaminating the diaphragm valve for the next fluid.

[0086] In a further embodiment of the invention, the sample channel has a throttle section with a reduced cross-section, in particular an elongated throttle section between the blood sample receptacle and an interface to the media channel.

[0087] Due to the throttle section, increased pressure is required to move a sample fluid through the sample channel and the adjacent channels. This simplifies fluid flow, as typically only small volumes of sample fluid need to be moved, which are subjected to only a slight overpressure or underpressure to be pumped through the sample channels. However, low pressures are difficult to control. Therefore, the pressure in the sample channels can be "artificially" increased by the throttle section, making the applied pressure easier to control. The throttle section preferably has a cross-section that is 50–95% smaller than the smallest cross-section outside the throttle section.

[0088] In a further embodiment, several interaction chambers, in particular arranged in parallel, are provided on the underside, into which separate membrane valve-controlled fluid channels open at opposite ends.

[0089] The provision of multiple interaction chambers offers the advantage that multiple fluids can be introduced into the different interaction chambers in parallel to interact with the associated sensor element surface. This allows for higher sample throughput in a shorter time.

[0090] Particularly preferably, the plurality of parallel arranged interaction chambers can be closed on the underside with a single sensor element, so that the interaction chambers each define a section on the sensor element surface that is in fluidic contact with the medium or the blood sample.

[0091] A further aspect of the invention provides that the fluid channels or groups of these fluid channels assigned to one end of the interaction chambers branch off from a common distribution channel which leads to a central media connection.

[0092] This simplifies the fluid flow towards the central media connection and there is only a single distribution channel at the media connection through which all media can be introduced into the one-way fluid guide assembly.

[0093] A further aspect of the invention provides that a separately valve-controlled outlet for waste medium and / or a separately valve-controlled connection for flushing fluid is present between the media connection and the diaphragm valves in the fluid channels.

[0094] For example, the valve-controlled waste medium outlet can be used to separately drain and collect used and / or contaminated medium. The valve-controlled flushing fluid connection, on the other hand, provides a fluid channel through which the connected fluid channels can be flushed with a flushing fluid. Separate flushing processes can be performed via this channel to clean the fluid channels of the disposable fluid guide assembly and remove any residual fluid.

[0095] In a further embodiment of the invention, a sample channel opens at the opposite ends of each interaction chamber, in particular wherein the sample channels of similarly directed ends end in series-positioned (ie arranged in a row) connections.

[0096] When a sample channel merges with a media channel, as optionally explained above, the common fluid channel piece leading into the interaction chamber forms both a section of the sample channel and the media channel, depending on which fluid is currently flowing through.

[0097] The arrangement of sample channels on the interaction chamber described above offers the advantage that several samples can be introduced into the respective interaction chambers simultaneously, thus achieving a higher sample throughput.

[0098] A further aspect of the invention provides that flushing channels branch off from the fluid channels at one end of the interaction chambers to a flushing fluid container, which can each be opened via their own flushing valves and which preferably merge into a central flushing channel.

[0099] This allows flushing, i.e. cleaning of the fluid channels, so that there is no contamination between different media or contamination of sample fluid by media residues.

[0100] In a further embodiment of the invention, the lower part has a plate-shaped section and a block-shaped section protruding from the plate-shaped section from the underside, in which the at least one interaction chamber is formed, which is open to this underside and / or wherein the upper part is plate-shaped.

[0101] The plate-shaped design allows for a particularly compact construction of the one-way fluid guide assembly and a simple design of the channels and chambers. Furthermore, a plate-shaped design offers the largest possible contact surface between the upper and lower sections, whereby the contact surface corresponds to a control surface used by the diaphragm valves to control fluid in the underlying fluid channels. The larger the control surface, the more precisely and variably the diaphragm valves can be positioned.

[0102] Furthermore, the block-shaped section offers the advantage that it can be introduced into a peripheral environment of a microfluidic device via a form-fit connection. For example, the block-shaped section can serve as a projection that can engage in a recess of a microfluidic device, whereby the disposable fluid guide assembly can be easily locked via the block-shaped section. The interaction chambers, which are closed by the sensor element(s), can be provided on the underside of the block-shaped section. In this variant, the block-shaped section can be inserted into a receptacle of a temperature control device, which ensures that the interaction chambers and the sensor element(s) are kept at a desired, constant temperature. The block-shaped section can be a separate part that is connected to the plate-shaped section of the lower part.

[0103] Furthermore, the upper part and the lower part can have at least one of the following properties: - the upper and lower parts are glued, welded or screwed together; - the upper and lower parts are injection-molded, in particular from cyclo-olefin copolymers (COC); and - the upper and lower parts have assembly aids, particularly in the form of guide pins or recesses.

[0104] Preferably, the upper and lower sections are welded together. This represents a particularly proven and reliable connection method, ensuring that no fluid leaks out of the sides of the disposable fluid guide assembly during subsequent operation.

[0105] Manufacturing the upper and lower sections as injection-molded components is a particularly simple and cost-effective manufacturing process. This is particularly important because the disposable fluid guide assembly is intended for single use.

[0106] Cyclo-olefin copolymers (COC) are the preferred material, particularly because they are particularly chemical-resistant and therefore particularly suitable for conveying medium and blood samples.

[0107] The assembly aids in the form of guide pins or recesses serve to integrate the disposable fluid guide assembly into the periphery of a microfluidic device with zero play and precise positioning. For this purpose, the guide pins can engage in corresponding recesses in the microfluidic device, or the recesses can engage in corresponding projections on the microfluidic device, thus allowing the disposable fluid guide assembly to be positioned particularly easily in a microfluidic device.

[0108] A further aspect of the invention provides that the sealing element is a flat, planar or profiled membrane that forms several membrane valves and separates several pneumatic and fluid channels from each other.

[0109] By using a flat, planar or profiled membrane, the sealing element can be designed particularly simply and cost-effectively as a diaphragm valve.

[0110] In particular, the membrane has cutouts to create a fluid connection for a blood sample between the top and bottom, thus providing a flow path for a blood sample from the top of the upper part to the bottom of the lower part and further into the interaction chamber. This offers the advantage that, despite the pneumatic actuation from the top of the upper part, a blood sample can simultaneously be introduced into the disposable fluid guide assembly via the top of the upper part. Therefore, it does not have to be laboriously pumped into the disposable fluid guide assembly from the side or bottom of the lower part.

[0111] A further aspect of the invention provides that the disposable fluid guide assembly has a plurality of interaction chambers which have a common sensor element and which each have their own first and second fluid channels at their ends.

[0112] In particular, providing each interaction chamber with its own separate first or second fluid channel enables particularly precise fluid control, independent of the other interaction chambers. Furthermore, this increases the throughput of surface treatments, and eliminates the need to use multiple sensor elements; instead, a single sensor element is required that can be engaged with the multiple interaction chambers.

[0113] According to a further aspect of the invention, several reservoirs for conditioning fluids are provided, which are fluidly connected to the interaction chambers via the fluid lines. Furthermore, the pneumatic unit is equipped with several drive valves, via which media valves can be selectively coupled to the reservoirs and can alternately apply positive pressure and negative pressure or positive pressure and ambient pressure to the reservoirs in order to pump the medium back and forth between the reservoirs and through the interaction chambers.

[0114] Consequently, the conditioning fluid in the storage containers can be fed contactlessly into the associated interaction chamber via fluid lines.

[0115] The term "conditioning fluid" is used synonymously with the term "medium" in this application. Both terms refer to a fluid stored in the reservoirs and used to condition the surface of a sensor element to be treated in the interaction chamber.

[0116] For example, the conditioning fluid can be selected from the group consisting of distilled water, isopropanol, rinsing fluid, PDS, NaPi, MEA, antibody fluid, TBS, various linker fluids, such as linkers based on silanes or thiol ethers, and Tbd.

[0117] “Fluid lines” refer to fluid-carrying connections between the storage containers and the interaction chamber.

[0118] The fluid lines can be, for example, hoses or similar flexible connecting elements.

[0119] In particular, the fluid lines can be reversibly coupled to the fluid channels within the disposable fluid guide assembly.

[0120] A further aspect of the invention provides that the pneumatic unit can be reversibly coupled to the disposable fluid guide assembly, in particular by arranging the disposable fluid guide assembly between the pneumatic unit and the media dosing units, i.e. the pneumatic unit can be non-destructively detached from the disposable fluid guide assembly, in particular repeatedly detached and non-destructively connected.

[0121] This offers the advantage that the disposable fluid guide assembly can be used to condition a sensor element and then disposed of. This prevents cross-contamination between conditioning fluids.

[0122] According to a further aspect of the invention, the first media dosing unit has a plurality of first storage containers for conditioning fluids, and the second media dosing unit has a plurality of second storage containers for conditioning fluids. From each of the plurality of first storage containers, a fluid channel serving as a media channel extends, which can be reversibly coupled to groups of first fluid channels or to all of the first fluid channels via at least one media valve. Furthermore, from each of the plurality of second storage containers, a fluid channel serving as a media channel extends, which can be reversibly coupled to groups of second fluid channels or to all of the fluid channels via at least one media valve, in particular, wherein each media channel is provided with its own media valve.

[0123] The above arrangement of storage containers and media channels allows for particularly precise routing of conditioning fluids from the respective storage containers of the first or second media dosing unit to the interaction chamber and back out again. Because each storage container is assigned a separate fluid channel as a media channel, separate from the other storage containers, the respective conditioning fluids in the storage containers can be introduced into the one-way fluid guide assembly separately, i.e., separately from one another. In this respect, the multiple media channels interact synergistically with their assigned media valves, which ensure that the fluid flows of the individual storage containers can be controlled separately from one another. For example, the media valves can be switched so that only one flow path from one storage container to the interaction chamber(s) is open at a time.

[0124] The provision of two separate media dosing units also allows conditioning fluids to be pumped back and forth between the first reservoirs and the second reservoirs of the first and second media dosing units. This allows the surface of a sensor to be conditioned as efficiently as possible in several steps using different media, while simultaneously using a minimal volume of conditioning fluid.

[0125] In particular, the first and second media dosing units are arranged in a mirror image of each other, in that each media dosing unit has the same number of reservoirs, each containing the same conditioning fluids, and is located on opposite sides of the interaction chambers. Mirror image does not mean that exactly the same distances to a fictitious mirror axis must be present, but rather that the media dosing units are arranged largely symmetrically and opposite each other on the opposite sides of the interaction chambers, or, in the case of a series arrangement of the interaction chambers, on the opposite sides of this row.

[0126] In a further advantageous embodiment, the media channels of the first media dosing unit combine to form a common media collection channel, which can be reversibly coupled to the disposable fluid guide assembly with at least one central media connection, and / or the media channels of the second media dosing unit combine to form a common media collection channel, which can be selectively connected to groups of or all of the second fluid channels via valves.

[0127] By providing a common media collection channel, the number of media channels or fluid channels in the one-way fluid guide assembly and the interfaces to the respective media dosing unit can be reduced overall, making the one-way fluid guide assembly more compact. Furthermore, fewer valves are required within the one-way fluid guide assembly to switch the fluid channels connected to the respective media channels. In this respect, the media valves allow only one conditioning fluid at a time to flow from a reservoir via its assigned media channel into the common media channel and be introduced into the one-way fluid guide assembly via the central media connection. There, the central media channel continues and branches off into the fluid channels, which ultimately lead to their own interaction chambers.

[0128] A common media collection channel of the second media dosing unit, which can be selectively connected to groups or all of the second fluid channels using valves, allows each reservoir of the second media dosing unit to be fluidly connected to the second fluid channels of the disposable fluid guide assembly. By introducing the required conditioning fluid from the corresponding media reservoir of the second media dosing unit, media escaping from the interaction chambers can flow to their central reservoir and back into the interaction chambers. Another fluid can then flow through all interaction chambers simultaneously and subsequently into its reservoir, and so on.

[0129] A further aspect of the invention provides that at least one disposal channel provided with an outlet valve branches off from the at least one common media collection channel, which opens into a disposal container for waste medium.

[0130] This allows used or contaminated conditioning fluids to be stored separately from the storage containers in the disposal container. Consequently, the disposal container and the connected disposal channel with outlet valve allow conditioning fluids to be drained out of the disposable fluid guide assembly and disposed of as needed without contaminating the remaining fluid channels. Rinsing fluid can also be removed from the piping system in this way.

[0131] In a further advantageous embodiment of the invention, at least one drive valve is assigned to the plurality of first storage containers for conditioning fluids and at least one drive valve is assigned to the plurality of second storage containers for conditioning fluids in order to apply overpressure or underpressure to each storage container of the plurality of first and second storage containers for conditioning fluids via its assigned drive valve, in particular wherein the drive valves of the assigned interaction chamber are alternately controlled such that one storage container is subjected to overpressure and the other to underpressure or ambient pressure.

[0132] The drive valve allows the reservoirs to be connected to a compressed air and / or vacuum supply of the pneumatic unit or the environment, allowing conditioning fluid contained in the reservoirs to be pumped in or out of the reservoirs without contact. Furthermore, the alternating actuation of the first and second reservoirs of the first and second media dosing units with positive or negative pressure or ambient pressure or ambient pressure serves to achieve contactless, bidirectional media fluid flow between the first and second media dosing units via the interaction chamber(s) in the disposable fluid flow assembly.

[0133] Each storage container can be assigned a drive valve. However, it is also conceivable that only one drive valve is assigned to all storage containers of the first and / or second media dosing unit.

[0134] The invention further relates to a protein defect diagnostic device comprising a microfluidic device according to one of the aforementioned aspects. The protein defect diagnostic device comprises a sensor element that closes at least one, in particular several, or all interaction chambers with its surface-treated upper side. Furthermore, the protein defect diagnostic device comprises an optical unit that has an IR source, an IR detector, and a beam path connecting the IR source and the IR detector through the one or more interaction chambers. The optical unit is configured to guide the IR radiation generated by the IR source via the sensor element onto the IR detector via the beam path in order to record an IR spectrum from the surface of the sensor element.

[0135] The protein defect diagnostic device enables contactless and thus contamination-free protein defect detection on the surface of the sensor element. This is achieved by directing IR radiation generated by the IR source onto the sensor element, which scans the candidate biomarkers bound to the surface of the sensor element and records an IR spectrum of these. The recorded IR spectrum can be used to draw conclusions about the defects of the proteins bound to the surface. In particular, it can be determined whether the proteins bound to the antibodies on the surface exhibit misfolding, which could indicate early neurodegenerative disease.

[0136] Furthermore, the advantages mentioned above for the microfluidic device also apply analogously to the protein defect diagnostic device. In this respect, reference is made to the above description.

[0137] According to a first aspect of the invention, the protein defect diagnostic device comprises a plurality of interaction chambers and a group of first blood sample receptacles, which merge into the associated first fluid channels via first sample channels, and a group of second blood sample receptacles, which merge into the associated second fluid channels via second sample channels, such that each interaction chamber is fluidly connectable only to its own first and second blood sample receptacles.

[0138] This design advantageously allows for the sample application to be performed in the interaction chamber, in addition to the conditioning and measurement functions of the protein defect diagnostic device. Therefore, all steps from the conditioning of a sensor element surface through sample application to the final irradiation of the sensor element surface can now take place in the interaction chamber.

[0139] Furthermore, multiple interaction chambers allow for multiple sensor surface sections to be conditioned, exposed to sample fluid, and irradiated in parallel. This allows the protein defect diagnostic device to process a higher overall sample throughput.

[0140] A further aspect of the invention provides that each sample channel is provided with its own shut-off valve to pump a blood sample to the interaction chamber when the shut-off valve is open. The shut-off valve allows the flow from the sample channel into the interaction chamber to be controlled in a targeted manner. In particular, mixing of the blood sample and conditioning fluid can be prevented, since the shut-off valve can be used to control the flow of blood sample into the fluid channels of the disposable fluid guide assembly.

[0141] A further advantageous embodiment of the invention provides that the plurality of first blood sample receptacles and the plurality of second blood sample receptacles are each assigned a separate connection to the pneumatic unit, which can be switched via at least one control valve such that each blood sample receptacle can be subjected to overpressure and underpressure or to overpressure and ambient pressure via the at least one control valve, in particular wherein the blood sample receptacles of an interaction chamber are alternately controlled such that one blood sample receptacle is subjected to overpressure and the other to underpressure or ambient pressure and the blood sample is pumped back and forth across the sensor element.

[0142] Similar to the first and second media dosing units, a blood sample can be pumped back and forth between the two blood sample receptacles by alternately applying negative pressure or ambient pressure and positive pressure to the first blood sample receptacle and the corresponding second blood sample receptacle. This enables particularly efficient sample application to the sensor element, as the surface of the sensor element is exposed to a constant fluid flow of the blood sample. This offers the particular advantage that the sensor or its surface can be treated with just a small volume of sample fluid. In this respect, the volume of sample fluid required for sample application can be reduced without impairing the sensitivity of the subsequent measurement. The very small amount of blood required here is much lower than in a circular line in which blood is pumped in a circle, for example by a peristaltic pump.

[0143] In a further aspect of the invention, each of the plurality of first and / or second blood sample receptacles is provided with a membrane element or a lid in order to cover a sample inlet on the blood sample receptacle in a liquid-tight, resealable manner, wherein the membrane element is designed in particular as a hydrophobic, gas-permeable membrane film which can be reversibly coupled to at least one control valve assigned to the blood sample receptacle in order to subject the blood sample receptacle to overpressure and underpressure or to overpressure and ambient pressure via the membrane element.

[0144] The membrane element or lid serves a dual function: to allow sample introduction into the blood sample receptacle and, after the sample has been introduced, to seal the blood sample receptacle liquid-tight. This allows the blood sample to be stored securely within the blood sample receptacle. This is ensured in particular by the hydrophobic design of the membrane film. Furthermore, due to the membrane film's gas permeability, the blood sample receptacle can be connected to a compressed air supply via the membrane film. This can be used to apply pressure and / or negative pressure or ambient pressure to the blood sample contained in the blood sample receptacle in order to move it into or out of the blood sample receptacle toward the disposable fluid guide assembly.This eliminates the need to provide a separate connection for the compressed air supply, since both the sample introduction and the compressed air supply take place via the membrane element.

[0145] The invention further relates to a method for applying a blood sample to a sensor element for a protein defect diagnosis and / or for conditioning a sensor element for a protein defect diagnosis with an aforementioned microfluidic device, wherein the method comprises a cycle with the following steps: a) passing a blood sample or a conditioning fluid from the first fluid channel through the interaction chamber into the second fluid channel; b) returning the blood sample or conditioning fluid along the second fluid channel through the interaction chamber into the first fluid channel;

[0146] In other words, the above method represents a bidirectional fluid flow of a conditioning fluid / blood sample across the surface of a sensor element. This enables efficient surface treatment or conditioning, as well as the use of a sensor element, while simultaneously requiring a low volume of conditioning fluid and blood sample. At the same time, the conditioning and sample flow across the surface is particularly uniform, as a fluid stream of conditioning fluid or sample fluid always flows along the surface of the sensor element. Furthermore, since the conditioning fluid / blood sample is constantly in motion, the conditioning of the surface is faster and more efficient compared to a method for treating the surface of a sensor element in which the sensor element is merely incubated in the conditioning fluid, i.e., the conditioning fluid is not moved.The same applies to the blood sample, which can be analyzed more quickly and safely.

[0147] A further aspect of the invention provides that steps a) and b) are repeated for a predetermined period of time or until a predetermined number of cycles is reached.

[0148] This allows the conditioning process to be controlled with particular precision, without the need for external manual intervention to stop the process at a given time.

[0149] In a further aspect of the invention, the method provides for detecting whether a fluid front has passed a specific section in the flow path, whereupon the flow direction is reversed.

[0150] This allows for precise determination of the point in time at which step a) and step b) are performed, i.e., started and ended. This can be determined either by measuring the elapsed time between the two steps. However, it is also conceivable that the fluid front is measured optically, in particular using a detection device. Furthermore, it can be provided that a predetermined waiting time is maintained between the individual cycles.

[0151] A further aspect of the invention provides that the method is first carried out with a conditioning fluid, in particular, wherein a cycle consisting of steps a) and b) is first carried out with a conditioning fluid. Subsequently, the method is repeated with steps a) and b), optionally with step c), using a sample fluid. Optionally, a rinsing process can be performed between the conditioning fluid and the application of the sample fluid.

[0152] The invention further relates to a method for analyzing protein defects in a blood sample, using a protein defect diagnostic device having sample receptacles, the method comprising the following steps: a) guiding a first blood sample along a first flow direction from a first sample receptacle through the interaction chamber into a second sample receptacle; b) returning the blood sample along a second flow direction, which is opposite to the first flow direction, from the second sample receptacle through the interaction chamber into the first sample receptacle; and c) Irradiating the surface of the sensor element with IR emitters to obtain an IR spectrum.

[0153] The core idea behind the method is that sample application can be performed using the smallest possible amount of blood sample. It has been shown that the volume of blood sample required for sample application can be reduced by repeatedly passing it over the surface of the sensor element. In this respect, pumping back and forth—that is, moving and returning the blood sample along the first and second flow directions—enables efficient sample application without compromising the sensitivity of the subsequent measurement.

[0154] Furthermore, the actual measurement step, namely step c), can follow the sample application, in which the surface of the sensor element is exposed to IR radiation. This works synergistically with steps a) and b), since the measurement process in step c) is very sensitive without the need for large amounts of blood sample volume in the previous steps a) and b).

[0155] Alternatively, the measurement can be taken while pumping back and forth.

[0156] Further features and advantages of the invention will become apparent from the following description and the accompanying drawings, to which reference is made. In the drawings: - Fig. 1 shows a schematic representation of a protein defect diagnostic device according to the invention with a microfluidic device according to the invention and an optical unit; - Fig. 2 in an isometric view the protein defect diagnostic device according to the invention with the microfluidic device according to the invention from Fig. 1; - Fig. 3 the fluid circuit diagram for the fluid guidance of the microfluidic device Fig. 2; - Fig. 4 shows an isometric view of an embodiment of the disposable fluid guide assembly of the microfluidic device of Fig. 2; - Fig. 5 shows a side view of the disposable fluid guide assembly from Fig. 4, with the section planes AA and BB; - Fig. 6 shows a plan view of the top of the disposable fluid guide assembly Fig. 4, with the cutting plane CC; - Fig. 7 shows a bottom view of the underside of the disposable fluid guide assembly Fig. 4; - Fig. 8 in an isometric view the detail B from Fig. 7, where detail B shows an enlarged view of the interaction chambers; - Fig. 9A a sectional view along the section plane BB from the Fig. 5 shows the disposable fluid guide assembly, with hatching omitted for clarity; - Fig. 9B a sectional view along the section plane AA from the Fig. 5 shows the disposable fluid guide assembly, with hatching omitted for clarity; - Fig. 10 an isometric sectional view along the section plane CC Fig. 6 to the one-way fluid guide assembly, with details C, D and E; - Fig. 11 is an enlarged isometric sectional view along section plane CC of the left side of the disposable fluid guide assembly of Fig. 10, with detail F; - Fig. 12 is an enlarged isometric sectional view along section plane CC of the right side of the disposable fluid guide assembly of Fig. 10; - Fig. 13 an isometric sectional view of detail F from Fig. 11, wherein detail F shows an enlarged cross-sectional view of a throttle section; - Fig. 14 an isometric plan view of detail A of Fig. 7, wherein detail A shows an enlarged bottom view of the throttle section; - Fig. 15 an isometric plan view of detail C of Fig. 10, the detail showing a valve at an interface between fluid channel and sample channel, with the section plane DD; - Fig. 16A and Fig. 16B Sectional views along the section planes D1-D1 ( Fig. 16A) or D2-D2 ( Fig. 16B) from Fig. 15 of the valve Fig. 15 and Fig. 16C an isometric sectional view along the section plane D2-D2 of Fig. 15; - Fig. 17A and Fig. 17B details D and E from Fig. 10, wherein detail D shows an enlarged view of a fluid channel valve and detail E shows an enlarged view of a fluid channel valve and a flush valve; - Fig. 18A and Fig. 18B each shows an isometric sectional view of two embodiments of the fluid channel valve from Fig. 17B; - Fig. 19 an isometric sectional view along the section plane BB of Fig. 5 on a sealing element and the lower part underneath; - Fig. 20 in a schematic flow diagram the process steps for producing the disposable fluid guide assembly from Figure from the Fig. 4 to 19; - Fig. 21A and Fig. 21B shows an isometric view of a sensor element holder, with and without a sensor element, with the section plane EE; - Fig. 22A and Fig. 22B each shows a front view of one of the two end faces of the sensor element holder from the Fig. 21A and Fig. 21B, with the section plane FF, - Fig. 22C a sectional view along the section plane EE from Fig. 21A; - Fig. 23 a sectional view along the section plane FF from Fig. 22A on the sensor element holder; - Fig. 24 an isometric view of a combination of the disposable fluid guide assembly from Fig. 4, as well as the sensor element holder with sensor element made of Fig. 21A, with the section plane GG; - Fig. 25 a sectional view along the section plane GG from Fig. 24 of the combination of disposable fluid guide assembly and sensor element holder made of Fig. 24; - Fig. 26 a sectional view of the sensor element holder from Fig. 21A with a centering unit in an uncoupled state; - Fig. 27 another sectional view of the sensor element holder from Fig. 21A and the centering unit Fig. 26 in a coupled state; - Fig. 28 an isometric view of a base block with centering elements as part of the centering unit from the Fig. 26 and Fig. 27, with the section plane HH; - Fig. 29 a sectional view along the section plane HH from Fig. 28, which shows the centering elements; - Fig. 30 an isometric representation of a container as a temperature control unit and centering unit for receiving the disposable fluid guide assembly from Fig. 4, with sensor element blocks and fluid inlet blocks, with section plane II; - Fig. 31 a sectional view along section plane II from the Fig. 30 through the container; - Fig. 32 an isometric view of a fluid inlet block from Fig. 30, with the cutting plane JJ; - Fig. 33 a sectional view along the section plane JJ from Fig. 32 of the fluid inlet block, with the section plane KK; - Fig. 34 a sectional view along the section plane KK from Fig. 32; - Fig. 35 an isometric view of a pneumatic unit with a drive unit; - Fig. 36 an isometric view of the underside of the pneumatic unit from Fig. 35; - Fig. 37 is a schematic flow diagram of the method steps for a method according to the invention for conditioning a sensor element for protein defect detection and for applying a sample to the sensor element; and - Fig. 38 a schematic flow diagram of the method steps for a method according to the invention for guiding fluid over a sensor element surface for conditioning and / or for applying a blood sample.

[0157] Fig. 1 shows a protein defect diagnostic device 10 for analyzing protein defects in a blood sample.

[0158] For this purpose, the protein defect diagnostic device 10 comprises a microfluidic device 12 which is configured to condition a surface of a sensor element for protein defect detection and / or to apply a sample to a conditioned surface.

[0159] In the embodiment according to Fig. 1, the protein defect diagnostic device 10 with the microfluidic device 12 is configured to both condition a surface of a sensor element for protein defect detection and apply a sample to the conditioned surface. It should be emphasized, however, that it is also possible to condition the surface in a device similarly reduced to conditioning as shown in the figures, and to examine the blood sample for protein defects in a separate device similarly limited to the application and analysis of the blood sample.

[0160] In the present case, the microfluidic device 12 comprises a pneumatic unit 14 and a first media dosing unit 16 as well as a second media dosing unit 18, wherein the pneumatic unit 14 can be reversibly coupled to the first and the second media dosing unit 16, 18 and is configured to alternately apply overpressure or underpressure or ambient pressure to them.

[0161] A reversible coupling of two components is possible in Fig. 1 highlighted with a double arrow.

[0162] Furthermore, the microfluidic device 12 comprises a first blood sample receptacle 20 and a second blood sample receptacle 22, which can each be reversibly coupled to the pneumatic unit 14, so that the pneumatic unit 14 can alternately apply overpressure and underpressure to the first blood sample receptacle 20 and the second blood sample receptacle 22.

[0163] In addition, the microfluidic device 12 has at least one interaction chamber 24, which is partially closed by a sensor element 26 on one side.

[0164] The sensor element 26 is accommodated in a sensor element holder 28 and fastened to it, so that a surface 30 of the sensor element 26 closes the interaction chamber 24 on one side (here the underside), ie in sections.

[0165] The interaction chamber 24 can be reversibly coupled to the first and second media dosing units 16, 18 as well as to the first and second blood sample receptacles 20, 22. In the coupled state, the interaction chamber 24 is fluidically connected to the first and second media dosing units and the first and second blood sample receptacles 20, 22 depending on the switching positions of some valves presented below.

[0166] Consequently, the interaction chamber 24 provides a defined area in the microfluidic device 12 in which at least one conditioning fluid and / or sample fluid can interact with the surface 30 of the sensor element 26. Details regarding the conditioning fluid and sample fluid, as well as the surface 30 of the sensor element 26, will be explained below.

[0167] Depending on the intended application of the protein defect diagnostic device 10, the microfluidic device 12 comprises either all or only some of the aforementioned components. For example, if the microfluidic device 12 is solely intended for conditioning the sensor element 26, the first and second blood sample intakes 20, 22 are omitted. Only the conditioning of the sensor element 26 then takes place in the interaction chamber 24.

[0168] If, however, the microfluidic device 12 is solely designed for the analysis of protein defect detection in a blood sample, then the first and second media dosing units 16, 18 are omitted. In the interaction chamber 24, only the sample is applied to the sensor element 26.

[0169] In the two aforementioned cases, the interaction chamber 24 and the pneumatic unit 14 remain.

[0170] However, as shown in the figures, a combination of the aforementioned embodiments is also conceivable, so that the protein defect diagnostic device 10 with the microfluidic device 12 is configured to first carry out a method for conditioning the sensor element 26 and subsequently a method for applying a sample fluid to the sensor element 26. For this purpose, the first and second media dosing units 16, 18 and the first and second blood sample receptacles 20, 22 are then provided.

[0171] Independently of the above-mentioned embodiments of the microfluidic device 12, some of the aforementioned components may be at least partially integrated into a disposable fluid guide assembly 32, such as those shown in the Fig. 4 to 8, although this is not to be understood as limiting.

[0172] In the Fig. In the embodiment of the microfluidic device 12 shown in Figure 2, the first and second media dosing units 16, 18 are arranged outside the disposable fluid guide assembly 32, and the first and second blood sample receptacles 20, 22 are integrated into the disposable fluid guide assembly 32, wherein the interaction chamber 24 is also integrated into the disposable fluid guide assembly 32. This embodiment will be described further below with reference to Fig. 4 to 19 are discussed in detail.

[0173] The protein defect diagnostic device 10 according to Fig. 1 further comprises an optical unit 34 to analyze protein defects in a blood sample.

[0174] The optical unit 34 comprises an IR source 36 and an IR detector 38, both arranged in a common optical housing 40. The IR source 36 is configured to generate IR rays, and the IR detector 40 is configured to measure the IR rays generated by the IR source 36. Furthermore, the IR source 36 and the IR detector 38 are radiation-connected via a beam path 42 that runs through the interaction chamber 24.

[0175] Basically, the optical unit 34 is configured to direct an IR beam generated by the IR source 36 onto the sensor element 26 via the beam path 42 onto the IR detector 40 in order to record an IR spectrum from the surface 30 of the sensor element 26.

[0176] To adjust the IR beam, several mirror elements 44 can be provided along the beam path 42, which reflect the IR beam from the optics housing 40 onto the surface 30 of the sensor element 26 and from there back into the optics housing 40 onto the IR detector 38.

[0177] Furthermore, the protein defect diagnostic device 10 comprises a control unit 46 (see Fig. 2), with a controller 48 and an evaluation unit 50, both of which are housed in a technical housing 52.

[0178] The controller 48 and the evaluation unit 50 are connected to each other and to the pneumatic unit 14 in a signal-transmitting manner in order to control the compressed air supply provided by the pneumatic unit 14. For this purpose, the evaluation unit 50 can receive certain signals from the pneumatic unit 14 in the form of parameters and / or measurement data, wherein the evaluation unit 50 transmits a control signal to the controller 48 based on these parameters and / or measurement data. Based on the control signal, the controller 48 can control the pneumatic unit 14.

[0179] In particular, the evaluation unit 50 can receive signals from detection units that monitor at least one flow-relevant parameter in the disposable fluid guide assembly 32 and forward it to the evaluation unit 50. The flow-relevant parameter can be a flow direction of a fluid, a flow velocity of a fluid, a fluid volume per unit of time, and the type of fluid, i.e., liquid or gaseous.

[0180] The control signal can, for example, be a signal for applying overpressure or negative pressure to the first and second media dosing units 16, 18 and the first and second blood sample receptacles 20, 22.

[0181] How to continue in Fig. As can be seen in Figure 2, the protein defect diagnostic device 10 further comprises a drive unit 54 configured to reversibly couple the pneumatic unit 14 to the disposable fluid guide assembly 32. Details of the drive unit 54 are explained further below in the description.

[0182] The drive unit is a reversible linear drive that can be moved either by motor or, as shown here, manually.

[0183] In addition, a centering unit 56 is provided in the protein defect diagnostic device 10, which can be reversibly coupled to the sensor element holder 28 so that the sensor element holder 28 can be aligned with the beam path 42, as shown in Fig. 2. This will also be explained further below in the description in connection with the Fig. 26 to 29 explained.

[0184] In addition, the protein defect diagnostic device 10, as shown in Fig. 2, a temperature control unit 58 which can be brought into contact with the back of the sensor element holder 28 and is configured, in the coupled state, to temperature-control the sensor element 26 via the sensor element holder 28 to a predetermined temperature. Details of the temperature control unit 58 are described further below in connection with Fig. 31 explained.

[0185] The fluid circuit diagram of a fluid guide in the microfluidic device 12 is explained in detail below. Fig. 3, which is referred to below.

[0186] The fluid circuit diagram of the fluid flow in Fig. 3 is divided into various sections, each corresponding to the aforementioned components. The fluid routing within the disposable fluid routing assembly 32 is shown in the center of the circuit diagram. The fluid routing of the first and second blood sample receptacles 20, 22 is integrated into the disposable fluid routing assembly 32. On the left side of this is the fluid routing of the first media dosing unit 16, and on the right side of this is the fluid routing of the second media dosing unit 18. The compressed air circuit within the pneumatic unit 14 is shown at the top of the circuit diagram.

[0187] The disposable fluid guide assembly 32 is in a coupled state with the first and second media dosing units 16, 18 and with the pneumatic unit 14.

[0188] First, the fluid guidance within the disposable fluid guidance assembly 32 is discussed.

[0189] Within the one-way fluid guide assembly 32, several fluid channels are provided, which will be explained below and can be switched via several valves. Unless otherwise stated, the valves described below are always check valves, in this case diaphragm valves, which can be actuated by positive or negative pressure. In particular, the check valves are designed to completely block or completely open the flow in a fluid channel or a fluid channel section.

[0190] In particular, the check valves are not designed to regulate the flow rate. Instead, the flow rate is controlled by the pneumatic unit 14 by applying positive or negative pressure to the first and second media dosing units 16, 18 and to the first and second blood sample receptacles 20, 22.

[0191] The interaction chamber 24 is arranged centrally in the one-way fluid guide assembly 32, with a first fluid opening 68 provided at a first end 66 of the interaction chamber 24 and a second fluid opening 72 provided at an opposite second end 70. A first fluid channel 74 opens at the first end 66 and is optionally fluidically connected to the interaction chamber 24 via at least one fluid channel valve 76. A second fluid channel 78 opens at the second end 70 and is fluidly connected to the interaction chamber 24 via a second fluid channel valve 80.

[0192] As in Fig. 3, however, there may also be a plurality of interaction chambers 24 from which a plurality of first fluid channels 74 and second fluid channels 78 extend, wherein each interaction chamber 24 is assigned only a first fluid channel 74 and only a second fluid channel 78.

[0193] In Fig. 3 In order to improve clarity, not all lines, channels, valves, chambers, etc. are provided with reference symbols, but only some examples, if they are units connected in parallel.

[0194] The fluid guide between the disposable fluid guide assembly 32 and the first media dosing unit 16 will now be discussed.

[0195] The circuit diagram of the fluid guide also shows that the first media dosing unit 16 is optionally fluidly connected to the first fluid channel 74 (here all first fluid channels 74) at the first end 66 of the interaction chamber 24 via at least the associated fluid channel valve 76.

[0196] More precisely, the first media dosing unit 16 has a first media channel 88, in this case a plurality of first media channels 88, which can be reversibly coupled to the first fluid channel 74 or the plurality of first fluid channels 74 via an associated first media valve 90, wherein a fluidic connection is present in the coupled state.

[0197] As in Fig. 3, however, there may also be a plurality of first media channels 88 which can be reversibly coupled to the first fluid channel 74 or the first fluid channels 74 via first media valves 90, ie each media channel has its own media valve 90.

[0198] Furthermore, the first media dosing unit 16 has at least one first storage container 94 into which the first media channel 88 opens or from which the first media channel 88 extends.

[0199] For example, the first reservoir 94 may be a liquid tank.

[0200] A conditioning fluid 96 is stored in the first storage container 94, wherein the conditioning fluid 96 is selected from the group consisting of distilled water, isopropanol, rinsing fluid, PDS, NaPi, MEA, antibody fluid, TBS, various linker fluids, such as linkers based on silanes or thiol ethers, and Tbd.

[0201] Preferably, a group of first storage containers 94 is provided, with at least one fluid channel extending from each storage container 94, serving as the first media channel 88. Here, too, for clarity, only a few media channels 88 are provided with reference numerals. Media channels 88 simultaneously form fluid channels.

[0202] Preferably, a different conditioning fluid 96 is arranged in each storage container 94, so that several of the conditioning fluids listed above can be provided.

[0203] More precisely, a section is provided between the first media channels 88 and the first storage containers 94, in which the first media channels 88 are designed as first fluid lines 100 in the form of hoses or pipes (see also Fig. 2).

[0204] The first fluid line 100 can extend into its storage container 94 and into the conditioning fluid 96 contained therein.

[0205] In addition, at least one first media control valve 104 in the pneumatic unit 14 is assigned to the first media dosing unit 16, which is configured to apply overpressure or underpressure to the first storage containers 94 in order to pump the conditioning fluid 96 contained therein into or out of the first storage container 94.

[0206] For example, each first reservoir 94 may be provided with a membrane (not shown here) that is gas-permeable but liquid-tight, so that the first media control valve 104 can couple to the membrane and apply overpressure or negative pressure to the interior of the first reservoir 94.

[0207] As in Fig. 3, first media control valves 104 are provided to apply overpressure or underpressure to the first reservoirs 94. In the circuit diagram shown in Fig. 3, a total of four media control valves 104 are provided, each of which is fluidly connected to at least one first storage container 94 via a first pneumatic line 108.

[0208] In the present case, first pneumatic lines 108 connect the first storage containers 94 with the first media control valves 104.

[0209] Each first pneumatic line 108 may, for example, be a hose or a pipe designed to withstand overpressure or underpressure.

[0210] The first media dosing unit 16 further comprises a singular first media collection channel 112, in which the group of first media channels 92 are combined after the media valves 90, and which can be reversibly coupled to the disposable fluid guide assembly 32 via a central media connection 114.

[0211] Furthermore, the central media connection 114 fluidically connects the first media collection channel 112 of the first media dosing unit 16 to a first distribution channel 116 provided in the disposable fluid guide assembly 32.

[0212] The first fluid channels 74 branch off from the first distribution channel 116. Thus, the first distribution channel 116 is fluidically connected to the associated interaction chamber 24 and thus to all interaction chambers 24 via an associated first fluid channel valve 76.

[0213] One option provides that the fluid channels 74 assigned to one end of the interaction chambers, or groups of these fluid channels 74, branch off from the common distribution channel 116 or multiple distribution channels, which lead to a central media connection 114. This also applies subsequently to the second fluid channels, which can also lead in groups to one common distribution channel or multiple distribution channels.

[0214] The fluid flow of the second media dosing unit 18 will be discussed in more detail below.

[0215] The circuit diagram shows that the second media dosing unit 18 is optionally fluidically connected to the second fluid channel 78 at the second end 70 of each interaction chamber 24 via at least the respectively associated second fluid channel valve 80.

[0216] The second media dosing unit 18 comprises at least one second, here several second, storage containers 118, which are filled with conditioning fluid 96. Each second storage container 118 can be designed in the same way as the first storage container(s) 94 of the first media dosing unit 16.

[0217] In the present case, as stated, a plurality of second storage containers 118 are provided, wherein an associated second media channel 122 opens into each of the second storage containers 118 or extends away from them.

[0218] Particularly preferably, each storage container 118 contains a different conditioning fluid 96. However, the storage containers 118 can also initially be empty in order to receive a conditioning fluid from the first storage containers 94. In principle, it is not necessary for the same number of first and second storage containers 94 and 118 to be provided.

[0219] For example, there may be more first storage containers 94 than second storage containers 118 or vice versa.

[0220] The conditioning fluid is again preferably selected from the group consisting of distilled water, isopropanol, rinsing fluid, PDS, NaPi, MEA, antibody fluid, TBS, various linker fluids, such as linkers based on silanes or thiol ethers, and Tb.

[0221] In Fig. 3, each second storage container 118 is assigned its own second media channel 122, which extends from the second storage container 118.

[0222] Each of the second media channels 122 can be reversibly coupled to the associated second fluid channel 78 via its own second media valve 126, with a fluidic connection being established between them in the coupled state. Alternatively, the media channel 122 can be reversibly coupled to groups of second fluid channels or to all second fluid channels via at least one media valve 126.

[0223] The second media valves 126 can be designed, in particular, as solenoid valves, so-called Lorentz force valves, to adjust the flow rate from the second media channels 122 to the second fluid channels 78. In Lorentz force valves, permanent magnets generate a constant magnetic field. A coil in the valve housing moves within the magnetic field. This creates a constant force that moves a diaphragm.

[0224] As in Fig. 3, each second media channel 122 can be reversibly coupled to each second fluid channel 78 via its second media valve 126.

[0225] More precisely, the second media channels 122 have a section to the second storage containers 118, in which the second media channels 122 are designed as second fluid lines 128 in the form of hoses or pipes.

[0226] Furthermore, the second fluid lines 128 can also extend into the second storage containers 118 and into the conditioning fluid 96 located therein.

[0227] Second media control valves 132 are assigned to the second media dosing unit 18, each of which is reversibly coupled to the second storage containers 118 via at least one pneumatic line 136 in order to apply negative or positive pressure to them. By applying negative or positive pressure, a conditioning fluid 96 stored in the second storage containers 118 can be pumped out of or into them.

[0228] Furthermore, a second media collection channel 140 is provided in the second media dosing unit 18, in which the second media channels 122 merge. In contrast to the fluid flow in the first media dosing unit 16, the second media collection channel 140 splits again toward the one-way fluid guide assembly 32 into second media channels 122, which correspond to the number of second fluid channels 78 in the one-way fluid guide assembly 32 and are each provided with a media valve.

[0229] As in Fig. 3, the second media collection channel 140 may, for example, be designed to change the number of incoming and outgoing second media channels 120.

[0230] In addition, between the second media channels 122, which branch off from the second media collection channel 140 in the direction of the disposable fluid guide assembly, and the second fluid channels 78, a section is provided in which the second media channels 122 are also designed as second fluid lines 128 (e.g., hoses or pipes).

[0231] As in Fig. 3, in this section the second fluid lines 128 (they thus form sections of the second media channels 122) can each be reversibly coupled to the second fluid channels 78 via a media connection 142.

[0232] In the area of ​​the media connections 142, a volume flow measuring unit 144 is provided for each fluid channel 78.

[0233] Between the first media dosing unit 16 and the second media dosing unit 18, a bypass channel 148 is also provided, which can be switched via a bypass valve 150. More precisely, the bypass channel 148 extends from the first media collection channel 112 to the second media collection channel 140 and fluidically connects the two.

[0234] A flow path of one of the conditioning fluids 96 between the first media dosing unit 16 and the second media dosing unit 18 is described below by way of example.

[0235] The conditioning fluid 96 is initially arranged in one of the first reservoirs 94. This reservoir can be pressurized via the associated first media control valve 104, so that the conditioning fluid 96 is pumped from the reservoir 94 and via the first fluid line 100 into its own, first media channel 88, where the conditioning fluid 96 encounters the first media valve 90.

[0236] After passing the first media valve 90, the conditioning fluid 96 flows into the first media collection channel 112 and from there via the central media connection 114 into the one-way fluid guide assembly 32.

[0237] The conditioning fluid 96 enters the first distribution channel 116 of the disposable fluid guide assembly 32 via the central media connection.

[0238] Following the first distribution channel 116, the conditioning fluid 96 is distributed among the first fluid channels 74 with fluid channel valves 76. After passing through the first fluid channels 74, the conditioning fluid 96 flows into the respective interaction chambers 24 and out of them again into the second fluid channels 78.

[0239] At the end of every second fluid channel 78, the conditioning fluid 96 passes through the second fluid channel valve 80 and exits the one-way fluid guide assembly 32 via the media connections 142. The conditioning fluid 96 then reaches the volume flow measuring unit 144 and the second fluid lines 128. After the second fluid lines 128, the conditioning fluid 96 passes through the second media collection channel 140.

[0240] A separate second reservoir 118 is provided for each conditioning fluid 96, so that the appropriate media valve 126 is opened to allow the conditioning fluid 96 to enter its second reservoir 118.

[0241] While the conditioning fluid 96 passes through the flow path just described, the second reservoir 118 can be subjected to negative pressure by the second media control valve 132, i.e., while the first reservoir 94 is subjected to positive pressure. The flow path of the conditioning fluid 96 described above is then reversed again. To do this, only the second reservoir 118 and the first reservoir 94 must be subjected to positive or negative pressure, respectively.

[0242] Each conditioning fluid 96 can thus be reversibly pumped back and forth through all interaction chambers 24 singularly by opening the corresponding valves between its storage containers 94, 118.

[0243] The remaining channels and valves are explained in more detail below.

[0244] The disposable fluid guide assembly 32 is further equipped with a first flushing channel 152, which extends from outside the disposable fluid guide assembly 32 into the latter and is associated with the first fluid channels 74, wherein each of the first fluid channels 74 is fluidly connected to the first flushing channel 152 via a first flushing valve 154. More specifically, the first flushing channel 152 opens at one end into a flushing container 156 provided outside the disposable fluid guide assembly 32, in which at least one flushing fluid 158 is stored and which can be reversibly coupled to the disposable fluid guide assembly 32, and at its other end into the distribution channel 116.

[0245] The rinsing fluid 158 can be selected from the group consisting of water, buffer solution, in particular PBS solution, and combinations thereof.

[0246] Furthermore, the disposable fluid guide assembly 32 is equipped with a plurality of second flushing channels 160 on the opposite side of the interaction chambers 24, which merge into a common flushing channel 162 within the disposable fluid guide assembly 32.

[0247] Each of the second fluid channels 78 is fluidly connected to a second flushing channel 160 via a second flushing valve 164.

[0248] The common flushing channel 162 opens into a flushing container 166 arranged outside the disposable fluid guide assembly 32, in which a flushing fluid 158 is also stored or into which flushing fluid can be pumped from the flushing container 156 and pumped back into it.

[0249] The flushing container 166 and the common flushing channel 162 can be reversibly coupled to the one-way fluid guide assembly 32, with the second flushing valve 164 forming a flushing fluid interface 168 between a second flushing channel 160 and a second fluid channel 78. In particular, the second flushing valve 164 is designed as a two-way valve.

[0250] The first rinsing container 156 and the second rinsing container 166 are also reversibly coupled to the pneumatic unit 14 so that they can be alternately subjected to overpressure or underpressure so that the rinsing fluid 158 can be pumped back and forth between the rinsing fluid containers 158 and 166 via the first and second fluid channels 74, 78 and the interaction chambers 24.

[0251] Furthermore, a first disposal channel 170 is provided, which is assigned to the first media dosing unit 16. The first disposal channel 170 has a first valve-controlled outlet 172 to a first disposal container 174. In the circuit diagram of the fluid guide, the first disposal channel 170 is fluidically connected to the common first media collection channel 112, so that contaminated and / or used conditioning fluids 96 can be disposed of via the first disposal container 174.

[0252] In the second media dosing unit 18, a second disposal channel 176 is provided, which leads to a second disposal container 180 via a second valve-controlled outlet 178. The second disposal channel 176 is fluidically connected to the common second media collection channel 140, so that contaminated and / or used conditioning fluids 96 can also be disposed of into the second disposal container 180 via this channel.

[0253] The disposable fluid guide assembly 32 is assigned a third disposal channel 182, which is connectable to a disposal container 186 via a third valve-controlled outlet 184. At its other end, the third disposal channel 182 opens into the first distribution channel 116, so that the latter is fluidly connected to the disposal container 186 via the disposal channel 182.

[0254] The third disposal container 186 is arranged outside the disposable fluid guide assembly 32 and can be reversibly coupled thereto.

[0255] The fluid flow of blood sample receptacles 20 and 22 is discussed in detail below.

[0256] Each of the blood sample receptacles 20 is mixed with a blood sample from another person so that the blood samples of several people can be analyzed simultaneously.

[0257] The first blood sample receptacles 20 are integrated into the disposable fluid guide assembly 32.

[0258] The first blood sample receptacles 20 are each fluidically connected to one of the first fluid channels 74 and thus to one of the interaction chambers 24 via a separate first sample channel 188, wherein the respective first sample channel 188 extends from the blood sample receptacle 20.

[0259] Each first sample channel 188 is provided with a first shut-off valve 190 so that the flow connection between blood sample receptacle 20 and its interaction chamber 24 can be switched.

[0260] In addition, second blood sample receptacles 22 are provided, which are also integrated into the disposable fluid guide assembly 32.

[0261] In particular, the second blood sample receptacles 22 are each fluidically connected to one of the second fluid channels 78 and thus to one of the interaction chambers 24 via a separate second sample channel 194, wherein the respective second sample channel 194 extends from the blood sample receptacle 22 or opens into it.

[0262] Every second sample channel 194 is provided with an associated second shut-off valve 196 so that the flow connection between blood sample receptacle 22 and interaction chamber 24 can be switched.

[0263] Specifically, the first blood sample receptacle 20 comprises several first blood sample receptacles 200.

[0264] Accordingly, the second blood sample receptacles 22 are also (second) blood sample receptacles 204, which are constructed identically to the first blood sample receptacles 200.

[0265] The first blood sample receptacles 200 are reversibly coupled to a first blood sample control valve 208 of the pneumatic unit 14, and the second blood sample receptacles 204 are reversibly coupled to a second blood sample control valve 210, wherein the first and second blood sample control valves 208, 210 are each configured to alternately apply overpressure and underpressure to the first and second blood sample receptacles 200, 204, so that a blood sample 212 can be pumped back and forth between the first and second blood sample receptacles 200, 204 through the associated interaction chamber 24.

[0266] The blood sample 212 is preferably blood serum, blood or blood plasma.

[0267] In order to fluidically separate the conditioning fluid 96 from the blood sample 212 and to prevent mixing of the fluids and thus contamination of the blood sample 212, a first, switchable interface 214 is provided between the first blood sample receptacle 20 and the interaction chamber 24, which is configured to fluidically separate the fluid flow from the conditioning fluid 96 and the blood sample 212.

[0268] More precisely, at the first interface 214, each first sample channel 188 from the first blood sample receptacle 200 meets the first fluid channel 74, which opens into the first media dosing unit 16. Therefore, a valve is provided at each first interface 214 that fluidically separates the first sample channel 188 from the first fluid channel 74. Both channels 74, 188 merge toward the interaction chamber 24 to form a common section 216 of the first fluid channel 74, which leads to the interaction chamber 74. The specific design of the first interface 214 is explained further below in the description.

[0269] Furthermore, a second interface 222 is provided between each second blood sample receptacle 22 and the associated interaction chamber 24, which second interface is configured to fluidically separate the fluid flow from the conditioning fluid 96 and the blood sample 212.

[0270] Therefore, a valve is provided at each second interface 222, which fluidically separates the second sample channel 194 from the second fluid channel 78. Both channels 78, 194 merge toward the interaction chamber 24 to form a common section 224 of the second fluid channel 78. The specific design of the second interface 222 is described in more detail below.

[0271] In order to apply negative or positive pressure to the first and second dosing units 16, 18, the first and second blood sample receptacles 20, 22 and the first and second rinsing containers 156, 166, these are reversibly coupled to the pneumatic unit 14.

[0272] The pneumatic unit 14 is explained in detail below.

[0273] For the compressed air supply, a vacuum line 230, an overpressure line 232 and a drive line 234 are provided in the pneumatic unit 14.

[0274] The vacuum line 230 is fluidly connected to a first pneumatic pump 236 and the overpressure line 232 and the drive line 234 are jointly connected to a second pneumatic pump 238.

[0275] The first and second pneumatic pumps 236, 238 are configured to provide a vacuum or compressed air supply in the respective strands.

[0276] The overpressure line 232 has a higher pressure than the drive line 234. For example, the overpressure line 232 can be pressurized to a pressure of approximately 1.5 bar relative to atmospheric pressure and the drive line 234 can be pressurized to a pressure of approximately 0.3 bar relative to atmospheric pressure.

[0277] To adjust the pressure, pressure regulators can be connected downstream of the second pneumatic pump 238 in the overpressure line 232 and the drive line 234.

[0278] Furthermore, each of the three strands 230, 232 and 234 is provided with at least one pressure gauge 240 so that the pressure in the respective strand can be monitored and adjusted if necessary.

[0279] Vacuum lines 242 are provided on the vacuum line 230, which open into associated pilot valves 244, into each of which an overpressure line 246 from the overpressure line 232 also opens.

[0280] Depending on the switching state, the pilot valves 244 fluidly connect the vacuum line 230 or the overpressure line 232 with at least one associated, switchable valve in or outside the one-way fluid guide assembly 12, for example the aforementioned shut-off valves in the one-way fluid guide assembly 32.

[0281] Overall, the first and second fluid channel valves 76, 80, the first and second shut-off valves 190, 196, the first flushing valve 154 and the second flushing valves 164 are each connected downstream of a pilot valve 244 and can be actuated via their pilot valve 244 with vacuum via the vacuum line 230 or with overpressure via the overpressure line 232, i.e. can be opened or closed.

[0282] To improve clarity, Fig. 3 In the top right corner, a pilot valve 244 and a shut-off valve to be switched by it are symbolically shown, as a placeholder for all pilot valves and their shut-off valves.

[0283] Further vacuum lines 242 branch off from the vacuum line 230, which, together with several drive line lines 248 branching off from the drive line 234, lead into several pilot control valves 250. Thus, each pilot control valve 250 is assigned a drive line 248 and a vacuum line 242.

[0284] A pneumatic line 251 extends from each pilot drive valve 250 to the respective drive valves 104, 208, 210 and 128 in order to apply pressure or vacuum to them.

[0285] Furthermore, several silencer elements 252 are provided in the pneumatic unit 14.

[0286] The following explains how the interaction chamber 32 and the parts that define it are kept constant at a predetermined temperature.

[0287] As already explained above, at least one interaction chamber 24 is provided in the disposable fluid guide assembly 32, to which a temperature control unit 58 is assigned.

[0288] The temperature control unit 58 comprises a temperature control element 254, which is in physical contact with the interaction chamber 24, in particular with the sensor element 26 adjacent to the interaction chamber 24, in a heat-transfer manner. Consequently, a heat-conducting connection 256 is also present between the temperature control element 254 and the temperature control unit 58, as shown in Fig. 3 is shown schematically.

[0289] The temperature control unit 58 is further connected to a temperature control device 258 via a temperature control circuit 260 for heat transfer, wherein the temperature control device 258 is configured to control the temperature control unit 58 to a predetermined temperature via the temperature control circuit 260. In this respect, temperature control is achieved by means of a temperature control fluid flowing through the temperature control circuit 260. For example, a liquid such as water or a mixture of water with an antifreeze such as glycerin, ethylene glycol, ethanol, and / or propylene glycol can be used as the temperature control fluid.

[0290] The predetermined temperature can then be passed on from the temperature control unit 58 via the heat-transfer connection 256 to the temperature control element 254 and thus to the interaction chamber 24.

[0291] To monitor whether the predetermined temperature is present in the interaction chamber 24, the temperature control circuit 260 and the interaction chamber 24 are provided with a plurality of cooling fluid temperature sensors 262. In particular, a sensor crystal temperature sensor 264 is provided, which monitors the temperature of the sensor element 26.

[0292] Furthermore, the temperature control unit 58 is connected to a compressed air supply via a compressed air connection 266 so that the temperature control circuit 260 can be easily dried and cleaned.

[0293] The Fig. 4 shows a concrete design of the disposable fluid guide assembly 32 from the previous figures.

[0294] The disposable fluid guide assembly 32 has a base 268 which includes a plate-shaped portion 270.

[0295] The plate-shaped section 270 has a fluid side 272 and a bottom side 274 facing away from it. Furthermore, the plate-shaped section 270 has two end sides 276 and two longitudinal sides 278 connecting the two end sides 276.

[0296] In the embodiment according to Fig. 4, the plate-shaped section 270 has a substantially rectangular basic shape.

[0297] A projection 280 extends laterally outwards from each of the long sides 278. The projection 280 has a rectangular basic shape and comprises (see Fig. 7) a centering hole 282 at each of its two corners and a centering element 283 in the form of a pin provided between the centering holes 282.

[0298] Furthermore, the one-way fluid guide assembly 32 (see Fig. 4 and Fig. 5) an upper part 284 which has a plate-shaped section 286 which is provided with an upper side 288 and a pneumatic side 290 facing away from it (see Fig. 5).

[0299] In the embodiment according to Fig. 4, the plate-shaped portion 286 has a substantially rectangular basic shape, which corresponds to the shape of the plate-shaped portion 270 of the lower part 268.

[0300] Between the top side 288 and the pneumatic side 290 there are two end faces 292 at the opposite ends, each of which is connected by two longitudinal sides 294.

[0301] Analogous to the lower part 268, the upper part 284 also has two rectangular projections 296 extending laterally outwards, at each of whose two corners a centering hole 298 is provided. Between the two centering holes 298, a centering element 283 (see Fig. 7) in the form of a recess.

[0302] As in Fig. As shown in Figure 5, the lower part 268 points with its fluid side 272 toward the pneumatic side 290 of the upper part 284a, so that the upper side 288 of the upper part 284 and the lower side 274 of the lower part 268 are freely accessible from the outside. In particular, the two plate-shaped sections 270, 286 lie congruently one above the other.

[0303] Most preferably, the upper part 284 and the lower part 268 are fastened to one another, for example by gluing them together in sections, welding them together or by fastening means, as in the Fig. 4 and Fig. 5 is shown.

[0304] In the following figures, the lower part 268 and the upper part 284 are fastened to each other via screw connections 300.

[0305] The outer contour of the upper and lower parts 168, 284 is explained in detail below.

[0306] The upper side 288 of the upper part 284 has two rectangular, elongated recesses 302, each arranged perpendicular to the extension direction of the first and second fluid channels 74, 78, in particular the first and second common sections 216, 224 of the first and second fluid channels 74, 78. In the present case, one recess 302 is assigned to the first fluid channels 74, and the other recess 302 is assigned to the second fluid channels 78.

[0307] A plurality of sensor windows 306 are embedded in the elongated recess 302, which extend close to the underlying first or second fluid channels 74, 78, in particular the common sections 216, 224 of the first or second fluid channels 74, 78.

[0308] Furthermore, the lower part 268 also has sensor windows 308 in the form of underside sensor windows 308 (see Fig. 7) extending from the underside 274 of the lower part 268 towards the top side 288 of the upper part 284.

[0309] The upper and lower sensor windows 306, 308 are arranged opposite one another, so that the first and second fluid channels 74, 78, in particular the common sections 216, 224 of the first and second fluid channels 74, 78, of the disposable fluid guide assembly 32 run between the upper and lower sensor windows 306, 308.

[0310] In addition, the top and bottom sensor windows 306, 308 are each configured to accommodate detection units. This will be explained in more detail below in the description.

[0311] As in Fig. 6, the upper side 288 has several pneumatic channel openings 310, only some of which are provided with reference numerals, to which pneumatic channels 311 (see Fig. 11) which run vertically and without interruption to the pneumatic side 290 of the upper part 284.

[0312] The pneumatic channel openings 310 are designed to be reversibly coupled to the pneumatic unit 14 in order to be subjected to overpressure or underpressure by the latter.

[0313] Fig. 7 also shows that a plurality of media channel openings 312 are arranged on the underside 274, which can be reversibly coupled to the first or second media dosing unit 16, 18, so that a conditioning fluid 96 flowing in from the first or second media dosing unit 16, 18 can flow into the lower part 268 via the media channel openings 312.

[0314] In addition to the media channel openings 312, a plurality of outlet openings 313 are provided on the underside 274, which can be reversibly coupled to the first or second rinsing container 156, 166 or to the third disposal container 186.

[0315] In the center of the underside 274, a block-shaped section 314 is provided, which projects downwards relative to the underside 274 of the plate-shaped section 270. The block-shaped section 314 is in Fig. 8 shown in detail.

[0316] A base surface 316 is provided on the side of the block-shaped section 314 facing away from the underside 274.

[0317] In the base surface 316, there are several elongated recesses in the form of interaction paths 318, which extend over the base surface 316 and run parallel to each other, forming the interaction chambers 24 in sections. According to the present embodiment, a total of two pairs of interaction paths 318 are provided, which are connected by longitudinal webs 319 (see Fig. 8) are objectionable to each other.

[0318] The first and second fluid openings 68, 72 are provided at the respective opposite ends of the interaction paths 318.

[0319] Each interaction path 318, together with the fluid openings 68, 72, is enclosed by a frame-like sealing element 320 that protrudes beyond the base surface 316 and, together with the interaction path 318 and the surface 30 of a sensor element 26, defines the interaction chamber 24 (the sensor element 26 has been omitted for clarity). The sensor element presses its surface 30 against the sealing elements 320 and closes the open side of the respective interaction chamber 24.

[0320] The sealing element 320 can in particular be designed as a sealing ring and is made of an elastic material.

[0321] Specifically, each of the two pairs of interaction tracks 318 is assigned an elongated double sealing ring which has the shape of the figure eight, so that two interaction tracks 318 share one long side of the double sealing ring.

[0322] Furthermore, a plurality of sleeve-shaped alignment projections 322 are provided on the base surface 316. The alignment projections 322 can be used to align the block-shaped portion 314 with a sensor element holder 28.

[0323] The block-shaped section 314 and the lower part 268 are designed as one piece, which does not necessarily have to be the case.

[0324] The internal part of the one-way fluid guide assembly 32 is explained in more detail below. This is particularly well illustrated in the Fig. 9A and Fig. 9B, which each show the unfolded disposable fluid guide assembly 32 along the section planes BB and AA, respectively. Fig. 9A shows the fluid side 272 of the lower part 268 and Fig. 9B the pneumatic side 290 of the upper part 284. For the sake of clarity, a sealing element 330 (see Fig. 4) in the Fig. 9A and Fig. 9B is omitted. This is in Fig. 19 is shown schematically, which will be briefly discussed below.

[0325] In principle, the upper part 284 on the pneumatic side 290 and the lower part 268 on the fluid side 272 each have a plurality of fluid channels formed by grooves 326. Recesses 328 on the pneumatic side 290 can be associated with the grooves 326 on the fluid side 272, which, together with a sealing element 330 arranged between the fluid side 272 and the pneumatic side 290, can act as valves.

[0326] The sealing element 330 is designed as a flat, profiled membrane that extends substantially completely over the fluid side 272.

[0327] Looking more closely (see Fig. 18), the sealing element 330 comprises a first membrane layer 332 and an overlying second membrane layer 334, wherein the first membrane layer 332 is arranged between the second membrane layer 334 and the fluid side 272.

[0328] Preferably, the first membrane layer 332 is thinner than the second membrane layer 334.

[0329] As in Fig. 19, the sealing element 330 has blood sample container recesses 336 so that a breakthrough through the first membrane layer 332 and the second membrane layer 334 is provided.

[0330] In the area of ​​the recesses 328, the sealing element 330 is part of a diaphragm valve 338, so that the fluid channels adjacent to the recesses 328 and formed as grooves 326 can be switched.

[0331] The fluid-carrying grooves 326 are arranged substantially on the fluid side 272 of the lower part 268, as in Fig. 9A. In more detail, the fluid side 272 has various grooves 326, each with different geometries.

[0332] In the top view of the Fig. 9A, the left and right sides of the fluid side 272 have different grooves. A central axis is symbolized by a dashed line. The left and right sides essentially correspond to the fluid flow in the circuit diagram in Fig. 3. In this sense, the left side is associated with the first fluid channels 74 and the right side is associated with the second fluid channels 78, as discussed below.

[0333] On the left side, a wave-shaped groove 340 is provided, which extends along or parallel to the end face 276 of the lower part 268. The beginning of the wave-shaped groove 340 is a dead end 339, and the other end represents an inlet opening 341 corresponding to the outlet opening 313.

[0334] The outlet opening 313 (see Fig. 7) on the underside 274 is fluidically connected via a bore to an inlet opening 341 (see Fig. 9A bottom left) on the fluid side 272.

[0335] The wave-shaped groove 340 has no direct connection to other grooves, but acts as a distribution channel.

[0336] The media inlet opening 345 on the fluid side 272 is fluidically connected to a media channel opening 312 (see Fig. 7) on the underside 274 and is spaced from the groove 340.

[0337] The groove 340 is spatially separated from partially linear grooves 346.

[0338] Each groove 346 extends to the center of the fluid side 272 and opens into a fluid interaction chamber opening 348, which fluidically connects the linear groove 346 to the interaction chamber 24.

[0339] The grooves 346 run parallel to each other in sections.

[0340] On the right side of the fluid side 272, linear grooves 346 can be seen, each extending from an associated media inlet opening 345 toward the center of the fluid side 272 and opening into a fluid interaction chamber opening 348, which fluidically connects the respective linear groove 346 with the associated interaction chamber 24. Thus, the right side has four inlets for the conditioning fluid 96.

[0341] A groove 346 on the left side is fluidically connected to a groove 346 on the right side via the respective interaction chamber 24.

[0342] Furthermore, each groove 346 is assigned an inlet opening 341 on the right side, which is located between the fluid interaction chamber opening 348 and the media inlet opening 345.

[0343] In the fluid circuit diagram of Fig. 3, the wave-shaped groove 340 corresponds to the first distribution channel 116 and the linear grooves 346 on the left side correspond to the first fluid channels 74 and the first common section 216, and the linear grooves 346 on the right side correspond to the second fluid channels 78 and the common section 224. The inlet openings 341 on the left side are assigned to the first flushing container 156 and the third disposal container 186, and the media inlet opening 345 corresponds to the central media connection 114. The inlet openings 341 on the right side are assigned to the second flushing container 166.

[0344] In addition, the pneumatic side 290 has several recesses 328, which, together with the sealing element 330, form diaphragm valves 338. Here, too, for the sake of simplicity, reference numerals are not provided for all valves, grooves, channels, openings, etc.

[0345] On each diaphragm valve 338 there is a pneumatic channel 311 (see Fig. 10), which opens into the recesses 328 and extends through the upper part 284 to the pneumatic side 290.

[0346] The fluid flow of the conditioning fluid 96 and the blood sample 212 in the disposable fluid flow assembly 32 is explained in more detail below. Fig. 10, which shows an isometric cross-sectional view along the section plane CC and provides an insight into the disposable fluid guide assembly 32.

[0347] In principle, the flow paths for the conditioning fluid 96 within the disposable fluid guide assembly 32 are different on the left and right fluid sides 272. However, it is also conceivable that both sides have the same fluid guide for the conditioning fluid 96.

[0348] In contrast to the fluid flow of the conditioning fluid 96, the fluid flow for the blood sample 212 is identical for both the left and right sides. Therefore, the design of the fluid flow for the blood sample 212 will be discussed first.

[0349] As in Fig. As shown in Figure 11, the blood sample holder 20 includes a blood sample receptacle 200 provided on the upper side 288 of the upper part 284. This receptacle encloses a cavity 351 for receiving the blood sample 212.

[0350] As in Fig. As can be seen in Figure 10, the blood sample container 200 has a cavity 352 in the upper part 284, which is adjoined by a cavity 354 in the lower part 268, forming the common cavity 351.

[0351] Viewed from the upper side 288 of the upper part 284, the blood sample containers 200 merge into one another and form a kind of tower-like structure with an upper end face 365.

[0352] In addition, each blood sample container 200 is provided on the common end face 365 with a sample inlet 366 through which a blood sample 212 can be introduced into the cavity 351.

[0353] Each sample inlet 366 is sealed in a liquid-tight manner by a membrane element 368, in particular a hydrophobic membrane. In particular, the membrane element 368 is designed to be gas-permeable, so that the cavity 351 in the blood sample receptacle 20 can be subjected to negative or positive pressure by the pneumatic unit 14. Alternatively, instead of the membrane element 368, a lid is provided at the sample inlet 366. This lid can be opened to fill the blood sample and then closed again.

[0354] As in Fig. 13, the cavity 354 in the lower part 268 has a bottom section 370 which is shaped as a trough which tapers conically towards the bottom and opens into a central opening 372.

[0355] The blood sample 212 can enter an outlet line 374 via the central opening 372, which extends vertically downward from the central opening 372 towards the bottom 274.

[0356] The outlet line 374 is followed by a throttle channel 375 which extends through a throttle section 376.

[0357] A constriction 378 is provided in the throttle channel 375. This can be achieved, for example, by tapering the cross-section of the throttle channel 375 in the region of the throttle section 376 due to the constriction 378.

[0358] As shown by Fig. 13 and Fig. As can be clearly seen in Figure 14, the constriction 378 is realized by a plate element 380, which is screwed from the underside 274 to the lower part 268 via several screw connections 382. As a result, the cross-section of the throttle channel 375 in the region of the constriction 378 is tapered to a slot-like cross-section due to the plate element 380, so that the cross-section of the throttle channel 375 is effectively reduced. The throttle channel 375 is delimited at the bottom by the plate element 380 and from above by the underside 274 of the lower part 268.

[0359] Furthermore, the throttle channel 375 is fluidically connected to a sample riser 384. In contrast to the constriction 378, the sample riser 384 again has a cross-section typical for the disposable fluid guide assembly 32. The sample riser 384 extends from the bottom 274 to the fluid side 272 and opens into a valve seat 386. This is particularly well illustrated by the Fig. 15 and Fig. 16 can be seen.

[0360] The sample riser line 384, the throttle channel 375 and the outlet line 374 correspond to the first sample channel 188 according to the circuit diagram of the fluid guide from Fig. 3.

[0361] The valve seat 386 forms a diaphragm valve 338 with a sealing element 330 resting on the valve seat 386, which in the fluid circuit diagram consists of Fig. 3 corresponds to the first interface 214.

[0362] As in Fig. 15, a first fluid channel 74 coming from the left runs into the first interface 214 and meets a branching point 388.

[0363] From the branching point 388, the first fluid channel 74 is divided into two sub-channels 390, each of which runs around a sleeve-shaped extension 392 of the sample riser 384 and reunites in a branching point 388 located behind it to form a common section 216, which Fig. 15 runs to the right and is fluidly connected to the interaction chamber 24.

[0364] In order to ensure a particularly dead-space-free contour of the first interface 214, the valve seat 386 is provided with two gusset-shaped noses 394, each of which is aligned in the direction of the two branching points 388, at which the two partial channels 390 reunite.

[0365] As in Fig. As can be seen particularly clearly in Figure 16A, the valve seat 386 has a concave shape between the gusset-shaped nose 394 and the opening of the sample riser 384. In this respect, the gusset-shaped nose 394 is a raised portion.

[0366] The section of the valve seat 386 that annularly surrounds the opening of the sample riser 384 is higher than each of the two gusset-shaped lugs 394. However, it is also conceivable for the gusset-shaped lug 394 to be lower, as long as a depression is present between the gusset-shaped lug 394 and the opening of the sample riser 384. Such a depression is particularly advantageous for preventing the diaphragm from sagging in the region of the branching point 388. In particular, the gusset-shaped lug 394 forms a support for the diaphragm, so that a further support in the form of a column or projection in the region of the branching point 388 can advantageously be omitted. In this way, the diaphragm can rest sealingly on the valve seat 386 in the unactuated state, and unhindered volume flow along the sub-channels 216 is also possible in this state.

[0367] Furthermore, as in the Fig. 16B and Fig. 16C, an anchoring point 396 in the form of a recess 398 is provided on the pneumatic side 290 of the upper part 284 in the region of the recess 328, into which the sealing element 330 can engage via a membrane projection 400.

[0368] Preferably, the anchoring point 396 is annular and circumferentially completely encloses the recess 328 of the first interface 214.

[0369] The Fig. 16A to 16C show the diaphragm valve 338 in a non-actuated state in which the sealing element 330 rests on the valve seat 386 and thus closes the sample riser line 384 in a fluid-tight manner.

[0370] Opposite the sample riser 384, a pneumatic channel 311 is provided, which fluidically connects the recess 328 to the upper side 288 of the upper part 284. In the actuated state, a vacuum is applied via the pneumatic channel 311, so that the sealing element 330 is pulled upward toward the upper side 288 into the recess 328, thereby opening the sample riser 384, which is then fluidly connected to the sub-channels 390.

[0371] The common section 216 is followed by the fluid interaction chamber opening 348, which leads into an interaction chamber line 402 (see Fig. 10 and Fig. 12).

[0372] The interaction chamber line 402 extends as a straight channel through the lower part 268 and through the block-shaped section 314 and opens into the interaction chamber 24 via the fluid opening 68 or 72. The fluid opening 68, 72 widens the interaction chamber line 402 in the direction of the interaction chamber 24 and forms a conical section 406 (see Fig. 10), which is opposite the interaction pathways 318.

[0373] The above description of the first blood sample intake 20 applies analogously to the second blood sample intake 22, in this respect reference is made to the above description.

[0374] The flow path 410 of the blood sample is explained in more detail below. The flow path 410 is indicated by the dashed line in the Fig. 11 and Fig. 12 shown.

[0375] First, the membrane element 368 or the cover is removed from the sample inlet 366, and the blood sample 212 is introduced into the blood sample receptacle 20. For example, the blood sample 212 can be manually pipetted into the sample inlet 366.

[0376] Subsequently, the sample inlet 366 is closed again by the membrane element 368. This can then be reversibly coupled to the pneumatic unit 14 so that the blood sample 212 located in the blood sample receptacle 20 can be subjected to positive or negative pressure. To move the blood sample 212, positive pressure is applied to the first blood sample receptacle 20 and negative pressure to the second blood sample receptacle 22. However, only positive pressure can be applied to the first blood sample receptacle 20.

[0377] Due to the applied overpressure in the blood sample intake 20 (see Fig. 11) the blood sample 212 is pressed into the central opening 372. From there, the blood sample 212 flows via the outlet line 374 and along the throttle section 376 via the throttle channel 375 into the sample riser line 384. The throttle section 376 ensures that the applied pressure increases, so that a higher overall pressure can be applied to the blood sample receptacle 20 to move the blood sample 212. An increased pressure is advantageous because, due to the small volume of blood sample 212, very low pressures would be necessary for transport, which, however, are difficult to control.

[0378] From the sample riser 384, the blood sample 212 enters the section of the interface 214. This section is closed by the diaphragm valve 338. By applying a vacuum on the pneumatic side 290 in the pneumatic channel 311 corresponding to and opposite the sample riser 384, the first membrane layer 332 is lifted from the valve seat 386 and pressed against the ceiling of the recess 328, so that the sample riser 384 is fluidically connected to the subchannels 390.

[0379] The blood sample 212 can then flow via the sleeve-shaped extension and the gusset-shaped nose 394 through the branching point 388 into the first common section 216 of the fluid channel 74 and further via the common section referred to as the interaction chamber line 402 into the interaction chamber 24.

[0380] From the interaction chamber 24, the blood sample 212 takes the same path into the blood sample receptacle 22 as described above for the first blood sample receptacle 20. In this respect, reference is made to the explanations above.

[0381] As already mentioned above, Fig. 10, the fluid flow of the conditioning fluid 96 is different for the left and right sides of the disposable fluid guide assembly 32. Therefore, the fluid flow for the conditioning fluid 96 will first be explained for the left side. For this purpose, Fig. 11 referred to.

[0382] A media riser 414 extends from the media channel opening 312 on the underside 274 and opens into the media inlet opening 345 (see Fig. 17A), opposite which is a recess 328 on the pneumatic side 290.

[0383] A pneumatic channel 311 is arranged opposite the media riser 414, which is fluidically separated from the media riser 414 by the sealing element 330, in particular the first membrane layer 332, wherein the sealing element 330 is shown in the Fig. 11 was omitted.

[0384] The sealing element 330 also forms a diaphragm valve 338, which is the first fluid channel valve 76 in the circuit diagram of the fluid guide according to Fig. 3 is.

[0385] An enlarged view of the corresponding second fluid channel valve 80 on the right side of the one-way fluid guide assembly 32 is shown in the Fig. 18A and Fig. 18B, which has the same structure as the first fluid channel valve 76.

[0386] The structure and operation of the fluid channel valve 76 are explained below using the second fluid channel valve 80, with reference to Fig. 18A, which is an enlarged view of the second fluid channel valve 80 of Fig. 17B shows.

[0387] In the non-actuated state of the second fluid channel valve 80, the media riser 414 is spatially separated from the second fluid channel 78 in the plane of the fluid side 272 by a partition wall. In particular, the first membrane layer 332 rests flatly on this partition wall, thereby concealing the media inlet opening 345 of the media riser 414 and the second fluid channel 78.

[0388] To create a fluidic connection between the media riser 414 and the second media channel 78, the recess 328 is a trough- or box-shaped recess 416 which, when viewed from the top side 288, conceals the media riser 414 and an initial section of the second fluid channel 78. Actuation of the second fluid channel valve 80 causes the first membrane layer 332 to be raised toward the recess 416, thereby creating a fluidic connection between the initial section of the second fluid channel 78 and the media inlet opening 345.

[0389] As in Fig. As further shown in Figure 18A, in addition to the first membrane layer 332, the second membrane layer 334 is provided, which is arranged above the first membrane layer 332 and faces the upper side 284. Furthermore, the second membrane layer 334 is cut out in the region of the box-shaped recess 416, so that only the first membrane layer 332 rests on the opening of the second fluid channel 78 and the opening of the media riser 414 in the unactuated state.

[0390] The above explanation applies equally to the first fluid channel valve 76 as in Fig. 17A and Fig. 18B. In contrast to the Fig. 18A and Fig. 17B, ​​the media riser 414 is in Fig. 17A is fluidly connected to the first distribution channel 116, 340 via the recess 416 when the first fluid channel valve 76 is in an open state. In contrast to Fig. 18A, is in Fig. 18B, only a first membrane layer 334 is provided. This can be held on the pneumatic side 290 of the upper part 284 via an anchoring point 396 in the form of a recess 398, wherein the sealing element 334 can engage in the recess 398 via a membrane projection 400. However, two membrane layers 332 and 334 can also be provided, as in Fig. 18A is shown.

[0391] The flow path 412 of the conditioning fluid 96 is explained in detail below. The conditioning fluid 96 can enter or exit the one-way fluid guide assembly 32 from both the left and right sides via the media channel openings 312. It is assumed below that the conditioning fluid 96 enters the one-way fluid guide assembly 32 from the right side.

[0392] The conditioning fluid 96 reaches the second fluid channel valve 80 via the media channel opening 312 and via the media riser 414. When the second fluid channel valve 80 is open, the conditioning fluid 96 flows from the media riser 414 into the second fluid channel 78.

[0393] From there, the conditioning fluid 96 flows via the two sub-channels 390 of the flushing fluid interface 168 to the second interface 222 (see Fig. 12).

[0394] At the second interface 222, the conditioning fluid 96 divides again into the two sub-channels 390 and reunites toward the second common section 224. It enters the interaction chamber line 402 via the fluid interaction chamber opening 348 and flows further into the interaction chamber 24.

[0395] From there (see Fig. 11), the conditioning fluid 96 again enters the next interaction chamber line 402 upwards towards the top side 288 and thus reaches the first common section 216.

[0396] The conditioning fluid 96 flows along the first common section 216 to the first interface 214.

[0397] There, the conditioning fluid 96 is divided according to the two sub-channels 390 and reunites in the first fluid channel 74 and meets the first fluid channel valve 76 further downstream.

[0398] When the first fluid channel valve 76 is open, the conditioning fluid 96 flows into the first distribution channel 116. From there, it encounters another first fluid channel valve 76 and flows through it into the media riser 414 and leaves the one-way fluid guide assembly 32 via the media channel opening 312. Of course, the flow path 412 of the conditioning fluid 96 can also be in the opposite direction.

[0399] Furthermore, Fig. 17B shows the flushing fluid interface 168 to the left of the second fluid channel valve 80. The flushing fluid interface 168 has the same structure as the first interface 214 explained above, with the difference that instead of the sample riser 384, a flushing fluid riser 418 is provided, which corresponds to the second flushing channel 160.

[0400] Fig. 20 shows a schematic flow diagram of the steps of a method for manufacturing the disposable fluid guide assembly 32.

[0401] In a first step S1, the lower part 268 is injection-molded. Preferably, the lower part 268 is made of COC because the material is fluid-repellent, preventing samples from adhering to the surface.

[0402] Optionally, the plate element 380 for the throttle section 376 can be injection-molded and then attached to the underside 274 of the lower part 268, thereby sealing the throttle channel 375 in a fluid-tight manner. Preferably, the plate element is also made of COC. Particularly preferably, the plate element 380 can be welded to the underside 274, in particular laser-welded.

[0403] Subsequently, the upper part 284 is injection-molded in a second step S2. The upper part 284 is preferably made of COC.

[0404] The sealing element 330 is then arranged between the lower part 268 and the upper part 284 (S3).

[0405] Finally, the upper and lower parts 268, 284 are fluidically connected to each other by clamping the sealing element 330 (S4).

[0406] Particularly preferably, the upper and lower parts 268, 284 are welded together, in particular laser welded.

[0407] The mounting of the sensor element is shown below using the Fig. 21 - 23 explained. In Fig. 21 A, two sensor elements 30 are attached to the common sensor element holder 28. The sensor element holder 28 has a plate-shaped body 420 (see Fig. 21A) with an essentially rectangular basic shape.

[0408] The plate-shaped body 420 comprises a front side 422, a rear side 424 facing away from it, and two longitudinal sides 426 between the front side 422 and the rear side 424, which each connect two end sides 428.

[0409] A pre-tensioning mechanism 432 is mounted in the wall on each of the long sides 426.

[0410] In the middle between the two pre-tensioning mechanisms 426, perpendicular to the direction of movement R V of the pretensioning mechanism 432, spaced-apart stop elements 434 are provided against which the sensor elements 30 are clamped. The direction of movement R V is in Fig. 22C shown.

[0411] In particular, the stop elements 434 are designed as projections in the form of longitudinal webs, each of which has an extension direction perpendicular to the direction of movement R v of the pretensioning mechanism 432.

[0412] As in Fig. As can be seen in Figure 21A, the pre-tensioning mechanism 432 is located centrally between the stop elements 434, viewed in its direction of movement.

[0413] In particular, at least the two stop elements 434 can each merge integrally into the sensor element holder 28.

[0414] Furthermore, the plate-shaped body 420 has recesses formed by recesses on its front side 422 for receiving the sensor elements 26. The stop elements 434 protrude from a bottom 438 of the recess.

[0415] The receptacles 436 are in particular a perpendicular to the direction of movement R v of the pre-tensioning mechanism 432 extending, continuous recesses.

[0416] Each pre-tensioning mechanism 432 is designed to act laterally in the direction of the two knock-off elements 434 and thus to tension a sensor element 26 arranged in the receptacle 436 laterally against the stop element 434 in a captive manner.

[0417] The pre-tensioning mechanisms 432 are formed mirror-symmetrically to a mirror plane 437, so that a pre-tensioning mechanism 432 and an associated receptacle 436 are present on each of the longitudinal sides 426 adjacent to the front side 422, wherein the mirror plane 437 extends through the stop elements 434.

[0418] As in Fig. As can be seen in Figure 21B, the bottom 438 of each recess is provided with a plurality of shoulders 440, each having an upwardly facing contact portion. The contact portions are designed as flat surfaces. Grooves 444 extend between the shoulders 440.

[0419] More precisely, the recess comprises a lateral contact section 441 formed as a shoulder 440 on each of its lateral edges, on which the sensor element 26 can rest flatly at the edge. Between the lateral contact sections 441, at least one central contact section 443 is provided, running parallel to the lateral contact section 441, on which the sensor element 26 also rests.

[0420] In a coupled state of sensor element 26 and sensor element holder 28, an air-filled reflection channel 445 (see Fig. 21A and Fig. 22A) was formed.

[0421] As in the Fig. 21A, Fig. 22A and Fig. 25, each sensor element 26 in each receptacle 436 forms two reflection channels 445 in the region of the grooves 444. Each reflection channel 445 has an inlet opening 446, which corresponds to a first end face 428, and an outlet opening 447, which corresponds to the opposite second end face 426 of the sensor element holder 28.

[0422] The preloading mechanism 432 is explained in more detail below.

[0423] Each preloading mechanism 432 is associated with a clamping element 448.

[0424] The clamping element 448 comprises a guide section 450 in the form of a block, which is accommodated in a matching recess 454 (see Fig. 23) is embedded in one of the longitudinal sides 426. With the guide section 450, the pretensioning mechanism 432 is guided linearly in the plate-shaped body 420. The recess 454 is in the direction of movement R vof the pre-tensioning mechanism 432 is longer than the block, so that it moves along the direction of movement R v of the pretensioning mechanism 432 can be guided linearly.

[0425] A guide web 456 projects upwards from the guide section 450 and extends along the direction of movement R v of the pretensioning mechanism 432. In particular, the guide web 456 and the guide section 450 merge into one another in one piece.

[0426] As in Fig. 22C, the guide web 456 extends through the one recess in the sensor element holder to the respective receptacle 436.

[0427] The guide web 456 has a contact nose 460 aligned in the direction of the stop element 434 (see Fig. 21B) has a flat front end with beveled flanks on both sides. The flat end of the contact nose 460 presses against the front of the sensor element 26 to securely clamp it in the receptacle 436.

[0428] To adjust the preload, the preload mechanism 432 is also assigned an adjusting screw 468, which can be screwed into a threaded bore 476 in the plate-shaped body 420 to different depths in order to move the preload mechanism 432.

[0429] Furthermore, a spring 482 is provided in an enlarged bore in the guide section 450, which spring 482 rotates the adjusting screw 468 and thus the pretensioning mechanism 432 against the direction of movement R v of the preloading mechanism 432.

[0430] To the side of the adjusting screw 468 (see Fig. 23), each clamping element 448 has two lateral openings 484 for receiving guide pins 486, which are pressed into the plate-shaped body 420 and serve as linear guides.

[0431] The clamping element 448 is in particular made of a softer material (e.g. plastic) than the plate-shaped body 420, the stop elements 434 and the sensor element 26.

[0432] In addition, a through hole 491 (see Fig. 23).

[0433] The sensor element 26 is a crystal block. This has a substantially rectangular basic shape and has a sensor element back 494 (see Fig. 22A) and two adjacent side surfaces 496, which terminate at the surface 30 of the sensor element 26. Between the surface 30 of the sensor element 26 and the sensor element rear side 494, beveled end faces 498 are provided.

[0434] Particularly preferably, the angle between the sensor element back 494 and the beveled front side is approximately 45 degrees.

[0435] In Fig. 22A further shows that the crystal block is placed with its sensor element backside 494 on the contact sections 441 and 443 for clamping into the sensor element holder 28. A side surface 496 of the crystal block rests against the end face of the contact nose 460. Tightening the adjusting screw 468 causes a linear advance of the clamping element 448 in the direction of the stop elements 434, so that the crystal block is clamped in the receptacle 436 between the stop element 434 and the clamping element 448.

[0436] Furthermore, as in Fig. 21B, a notch 500 is provided in the plate-shaped body 420 in the area around the exit opening 447 and the inlet opening 446, so that the beveled end faces 498 toward the rear side 424 are not covered by the base 438 or the receptacle 436. As a result, an IR beam can impinge freely and almost perpendicularly on the beveled end face 498.

[0437] The sensor element holder 28 together with the sensor elements 26 accommodated therein can be engaged with the disposable fluid guide assembly 32, in particular with the base surface 316 of the block-shaped section 314.

[0438] The coupled state of the sensor element holder 28 with the sensor element 26 accommodated therein and the disposable fluid guide assembly 32 is shown in Fig. 24 shown.

[0439] For this purpose, the sensor element holder 28 is brought into planar contact with its front side 422 on the section of the base surface 316 surrounding the interaction paths 318 and is fixed via upper-side recesses 502 provided on the front side 422 of the sensor element holder 28 (see Fig. 21B) to the block-shaped section 314 by its sleeve-shaped, protruding alignment projections (see Fig. 8) precisely penetrate the recesses 502. Screws 600 then extend through the central holes of the alignment projections 322 and are screwed into internal threads in the block-shaped section 314 to press the sensor elements 26 against the block-shaped section 314 and close the interaction chambers 24 previously open on this side.

[0440] In order to attach the sensor element holder 28 to the disposable fluid guide assembly 32 in a manner that is secure from confusion and precisely positioned in the installation position, an alignment projection 322 and a recess 502 are, for example, larger in diameter than the others.

[0441] The sensor element holder 28, which is attached to the disposable fluid guide assembly 32 and contains the sensor element 26, can then be coupled to the optical unit 34 of the protein defect diagnostic device 10. For this purpose, the sensor element holder 28, with the sensor element 26 contained therein, must be aligned in the beam path 42 to record an IR spectrum of the surface. Alignment is performed by the previously mentioned centering unit 56, which is explained in more detail below.

[0442] In order for the sensor element holder 28 to interact with the centering unit 56, the sensor element holder 28 is provided with an underside alignment geometry in the form of an elongated hole 606 and a round hole 608, which will be explained below with reference to the Fig. 26 - 30 will be discussed in more detail.

[0443] The centering unit 56 has a contact side in the form of the base 616 (see Fig. 27) which can be reversibly coupled to the sensor element holder 28 and on which the sensor element holder 28 rests flat with its rear side 424. This is exemplified in the Fig. 26 and Fig. 27 shown.

[0444] Furthermore, in the Fig. 26 and Fig. 27 clearly shows that the centering unit 56 has the shape of a container 612. Preferably, the container 612 is made of a heat-conducting material, preferably a metallic material or an alloy.

[0445] The term "container" in the context of accommodating a portion of the disposable fluid guide assembly 32 together with the sensor element holder 28 and sensor element 26 means that a receptacle for these parts is formed here to enable heat supply or heat dissipation from multiple sides. This does not require a closed or fluid-tight container, but rather a base 616 and one or more side walls 618 for heat transfer. Optionally, the base 616 and side wall or side walls 618 can also be in contact with the sensor element holder 28 and the disposable fluid guide assembly 32. However, if the block-shaped section 314 is surrounded by the container 612 on all sides, heat transfer is maximized.

[0446] A central recess 614 is provided in the container 612, which is defined by a bottom 616, a container opening opposite the bottom 616 and four side walls 618.

[0447] The floor 616 is closed, surrounded by the four side walls 618 in a frame-like manner.

[0448] The shape of the central recess 614 preferably corresponds to the shape of the cross section of the block-shaped section 314 and / or the sensor element holder 28 in order to accommodate them without a large lateral gap. In the present case, the central recess 614 therefore has a rectangular basic shape.

[0449] As in Fig. As shown in Figure 27, the sensor element holder 28, which is equipped with the sensor element 26, can be inserted into the central recess 614 together with the block-like section 314, so that the rear side 424 rests flat on the base 616. The base 616 forms the contact side of the centering unit 56.

[0450] In order to align the sensor element holder 28 in the beam path 42, the centering unit 56 has two centering elements. These are located closer to the Fig. 28 and Fig. 29 explains.

[0451] The centering elements are designed as spring-loaded guide pins 622, each of which is guided in an associated through hole 624 in the bottom 616 of the container 612.

[0452] As in Fig. 28, the guide pins 622 are not anchored in the container 612, but in a base block 626 which is arranged below the container 612 and supports it.

[0453] The base block 626 has a substantially U-shaped profile, with two feet 625 and a support surface 627 on which the container 612 can be mounted. The guide pins 622 are also anchored in the support surface 627. The base block 626 can, for example, be attached to a base plate (not shown here) via its two feet 625.

[0454] Each of the two guide pins 622 has a conical end 628 which faces away from the base block 626 and projects into the central recess 614 of the container 612.

[0455] The conical end 628 is followed by a shaft 630 (see Fig. 27), which extends laterally through the through-hole 624 in the base 616 of the container 612 and terminates in a centering recess on the contact surface of the base block 626, where it is anchored. Alternatively, the guide pins 622 can also be conical over the entire area in which they extend into the sensor element holder 28.

[0456] A preloading mechanism 634 with springs 642 is assigned to the centering recess to axially spring-load the guide pins 622 upward. To accommodate the springs 642, the guide pins 622 have a widened shaft section that is mounted in the base block 626.

[0457] The guide pins 622 can deflect in the axial direction to such an extent that the rear side 424 of the sensor element holder 28 strikes the bottom 616.

[0458] Centering via the centering unit 56 can be carried out as follows (see Fig. 27). The sensor element holder 28 is first attached to the disposable fluid guide assembly 32 and can then be inserted with the rear side 424 first into the central recess 614, with a guide pin 622 engaging in the elongated hole 606 and a guide pin 622 engaging in the round hole 608. The sensor element holder 28 is thus aligned in the xy plane. For alignment along the z-axis and perpendicular to the z-axis, the sensor element holder 28 is pressed further towards the base 616, whereby the guide pins 622 give way and guide the sensor element holder 28 to the base 616, where it comes into contact with its rear side 424. The sensor element holder 28 is thus aligned in the z-axis and perpendicular to it. The elongated hole 606 has an oval contour or is chamfered so that the guide pin 622 can engage better.

[0459] Furthermore, the container 612 is provided with two beam path shafts 645 (see Fig. 27 and Fig. 28) which extend through two side walls 618, are arranged opposite each other and open into the central recess 614.

[0460] Consequently, the underside alignment geometry and the centering elements are coordinated with each other in such a way that the inlet opening 446 and the outlet opening 447 each point in the direction of one of the two beam path shafts 645.

[0461] Furthermore, the beam path shafts 645 each terminate at the base block 626 with their end facing away from the recess 614, wherein the base block 626 also contains beam path shafts 645 corresponding to and adjoining the beam path shafts 645 in the container 612. These also extend essentially completely through the base block 626. The beam path shafts 645 are configured to receive the beam path 42 and guide it from the optical unit 34, which is typically arranged below the base block 626, via the beam path shafts 645 into the recess 614, into the sensor element 26, and out again.

[0462] Typically, the two beam path shafts 645 extend at a 45° angle to a plane in which the bottom 616 of the container 612 lies, so that the beam path has a right angle to the beveled end face 498.

[0463] Furthermore, a leakage protection unit (not shown here) can be provided, with a collecting basin (not shown here) that at least partially, preferably completely, surrounds the container 612 and a sensor (not shown here) for detecting fluid in the collecting basin, which is connected to the controller 48, which is designed to output a signal when fluid escapes.

[0464] Furthermore, the container 612 (see Fig. 30) has two media connection blocks 646, each of which is accommodated in a separate receiving opening 648 in the container 612. As mentioned, the media connection blocks 646 serve to quickly and safely reversibly couple the conditioning fluid-carrying channels in the disposable fluid guide assembly 32 to the storage containers 94 and the disposal containers 174.

[0465] The receiving openings 648 for the media connection blocks 646 have an elongated, box-like shape and are provided on two opposite sides of the container 612. The two media connection blocks 646 will be discussed in more detail below in the description.

[0466] Furthermore, the container 612 has two receiving openings 650 for sensor element blocks 652, as shown in Fig. 30 is shown.

[0467] The receiving openings 650 for sensor element blocks 652 have an elongated, box-like shape and are provided on opposite sides of the recess 614. In particular, a receiving opening 650 for sensor element blocks 652 is arranged between a receiving opening 648 for media connection blocks 646 and the central recess 614.

[0468] In particular, the two sensor element blocks 652 may each be detection units 653 equipped with optical sensors 651.

[0469] The detection units 653 are configured to contactlessly monitor the fluid flow adjacent to the ends 66, 70 of the interaction chamber 24.

[0470] For example, the detection unit 653 may be a source for generating radiation with specific wavelengths with which the fluid channels of the disposable fluid guide assembly 32 can be irradiated, or it may be a detector 684 that can detect radiation with specific wavelengths.

[0471] On the side of each of the two recess openings 650 facing away from the recess 614, a cable duct 654 is provided, which extends to the outer contour of the container 612 and connects it to the recess opening 650. Cables can be laid in the cable ducts 654 in order to connect the sensor element blocks 652 to the control unit 46, in particular the evaluation unit 50 and the controller 48, in a signal-transmitting manner.

[0472] Furthermore, the two receiving openings 650 are each delimited by a wall 656 on a side facing the receiving openings 648, so that the sensor element blocks 652 are received in a securely positioned manner.

[0473] Above this, on the bottom 616 of the container 612, there is a thermosensor element 660 which projects relative to the bottom 616, is axially prestressed and resiliently mounted (see Fig. 31).

[0474] The thermal sensor element 660 extends in the coupled state into the through hole 491 in the sensor element holder 28 to detect the temperature of the sensor element back side 494 of the sensor element 26.

[0475] The media connection blocks 646 are described below using the Fig. 32 to 34 are explained in more detail.

[0476] Each media connection block 646 has a block-shaped housing 686 with a top side 688 and a bottom side 690 arranged opposite thereto.

[0477] Between the top side 688 and the bottom side 690, end faces 692 extend at the opposite ends, which are each connected to one another via two longitudinal sides 694.

[0478] The media connection block 646 is received with the bottom 690 first in the receiving opening 648 so that the top 688 is exposed.

[0479] On the upper side 688, a plurality of first media inflow openings 698 are provided, only some of which are provided with reference numerals, as well as a plurality of second media inflow openings 700, wherein the plurality of first media inflow openings 698 are assigned to one longitudinal side 694 and the plurality of second media inflow openings 700 are assigned to the other longitudinal side 694. In more detail, the plurality of first media inflow openings 698 and the plurality of second media inflow openings 700 each lie on a straight line.

[0480] The first media inflow openings 698 and the second media inflow openings 700 of the upper side 688, each arranged in a row, are designed to be reversibly coupled to the media risers 414 of the disposable fluid guide assembly 32.

[0481] The first media inflow openings 698 are each fluidically connected to openings 698' on one longitudinal side 694 and the second media inflow openings 700 are each fluidically connected to openings 700' on the other longitudinal side 694 via L-shaped media channel sections 702 (see in particular Fig. 34).

[0482] The first openings 698' and the second openings 700' on the longitudinal sides 694 are designed to be reversibly coupled to the first or second fluid lines 100, 128 of the first and second media dosing units 16, 18, wherein a fluidic connection is present in the coupled state.

[0483] In the present case, eight first media inlet openings 698 and three second media inlet openings 700 are provided on the top side 688 and on a longitudinal side 694. Of course, the number can be varied.

[0484] Furthermore, the upper side 688 can have a flushing fluid connection 704 which is fluidically connected to a flushing fluid connection 704' on the longitudinal side 694 via an L-shaped flushing fluid channel section 706.

[0485] Furthermore, two disposal channel connections 708 are provided on the upper side 688, which are each fluidically connected via an L-shaped disposal channel section 710 to a disposal channel connection 708' on the longitudinal sides 694.

[0486] Advantageously, the media connection block 646 just described can be used for both the left side of the disposable fluid guide assembly 32 and the right side of the disposable fluid guide assembly 32, since two different flow paths are provided in a single component through the plurality of first and second media inflow openings 698, 700. In other words, depending on the application, either the first media inflow openings 698 or the second media inflow openings 700 are coupled to the media risers 414 of the disposable fluid guide assembly 32 and to the fluid lines 100, 128 of the first and second media dosing units 16, 18.

[0487] Furthermore, on the top side 688 (see Fig. 33) a sealing element 712 in the form of a flat, elastic membrane is provided, which has a plurality of recesses that correspond to the underlying media inflow openings 698, 700 on the upper side 688. The sealing element 712 is designed, when coupled to the media risers 414 of the disposable fluid guide assembly 32, to seal the fluidic connection by clamping the sealing element 712 flatly between the upper side 696 and the underside 274 of the lower part 268 and elastically deforming it.

[0488] Furthermore, the media connection block 646 has on its upper side 688 alignment geometries 718, which are connected to counter-alignment geometries 720 (see Fig. 36) are engageable on the one-way fluid guide assembly 32 to align with the one-way fluid guide assembly 32.

[0489] The alignment and counter-alignment geometries 718, 720 may, for example, be corresponding pins and openings that each engage with each other during coupling.

[0490] The media connection block 646 is equipped at its two opposite ends on the underside 690 with an anchor pin 722, with which it is received in corresponding holes with an oversize in the area of ​​the receiving opening 648.

[0491] Optionally, the anchor pins 722 can be assigned a locking mechanism provided in the receiving opening 648, so that the receiving openings 648 can be reversibly coupled to the media connection blocks 646. This allows the media connection blocks 646 to be easily removed from the receiving openings 648 and cleaned.

[0492] Furthermore, the media connection blocks 646 can be deflected towards the rear side 424 of the sensor element holder 28 and / or tilted in several spatial directions and are in particular resiliently mounted.

[0493] The resilient mounting is achieved by a first pair of springs 724, which support the underside 690 against the top of the associated receiving opening 648.

[0494] In addition, a plurality of second springs 726 are provided, particularly between the first pair of springs 724. The plurality of second springs 726 are also associated with the underside 690, but extend almost entirely into the block-shaped housing 686. As a result, only a portion of the group of second springs 726 protrudes from the underside 690. A gimbal suspension is simulated via the springs 724, 726.

[0495] The following section will discuss the temperature control unit 58 in detail. This is particularly well suited to Fig. 31 can be seen.

[0496] The temperature control unit 58 comprises the temperature control element 254, which can be brought into surface contact with the rear side 424 of the sensor element holder 28. The temperature control unit 58 is configured to bring the sensor element 26 to a predetermined temperature when the sensor element holder 28, sensor element 26, and temperature control element 254 are coupled.

[0497] The predetermined temperature is preferably room temperature. Room temperature is defined as a temperature between 17°C and 26°C.

[0498] Particularly preferred, as shown in the present case, is the entire container 612 or sections of it forming the temperature control element 254. This allows a particularly compact design of the protein defect diagnostic device 10 to be achieved.

[0499] In the coupled state between the disposable fluid guide assembly 32 and the temperature control element 254, the interaction chamber 24 can be received together with the sensor element holder 28 and the sensor element 26 in the recess 614, so that the rear side 424 of the sensor element holder 28 rests on the bottom 616 of the container 612, in particular wherein the side walls 618 of the disposable fluid guide assembly 32 and / or the sensor element holder 28 rest on side walls 618 of the container 612 or are only minimally spaced from them.

[0500] Consequently, the block-like portion 314 protruding from the underside 274 of the lower part 268 is completely received in the container 612.

[0501] As in Fig. 31, the tempering element 254 comprises at least one tempering channel 728 in the interior of the container 612, which passes through one or more side walls 618 and / or the bottom 616 of the container 612.

[0502] Particularly preferably, a plurality of temperature control channels are provided that extend through the container 612. For this purpose, the container 612 has an inlet 732 and an outlet 734, between which the one or more temperature control channels 728 extend in the container 612.

[0503] In other words, the temperature control channels 728 completely surround the circumference of the recess 614, so that the latter is temperature-controlled particularly evenly. Since the temperature control channels 728 extend almost entirely through the interior of the container, the media connection blocks 646 are also advantageously temperature-controlled.

[0504] A temperature control fluid (not shown here) flows through the temperature control channel 728, which is introduced into it by the temperature control device 258. The temperature control device 258 tempers the temperature control fluid to the predetermined temperature or to a temperature slightly higher or lower than the predetermined temperature in order to compensate for temperature losses during transport.

[0505] The temperature control device 258 is arranged outside the container 612 and is fluidically coupled to the inlet 732 and the outlet 734, creating the aforementioned temperature control circuit 260. In this circuit, the temperature control fluid is introduced from the temperature control device 258 into the inlet 732 of the container 612. There, it flows through the temperature control channels 728, thereby controlling the temperature of the container 612. This can bring the sensor element holder 28 and thus also the sensor element 26 to the predetermined temperature, since they are connected in a heat-transfer manner when coupled.

[0506] The pneumatic unit 14 is discussed in detail below. Fig. 35 and Fig. 36.

[0507] Specifically, the pneumatic unit 14 is designed as a pneumatic connection block 758, which has a bottom side 760 facing the disposable fluid guide assembly 32 and a top side 762 facing away therefrom.

[0508] The top side 762 is provided with a plurality of pneumatic units 764 which are fluidly coupled to pump inlets 766 provided on the top side 762.

[0509] As in Fig. 36, the underside 760 has a media metering interface 768 at each of the opposite ends, which is provided with an elastic sealing membrane 770, at which pump outlets 772 open, which are fluidly connected to the pump inlets 766 on the upper side 762 and of which only some are provided with reference numerals.

[0510] The sealing membrane 770 therefore has recesses corresponding to the pump outlets 772.

[0511] Each media dosing interface 768 is configured to fluidly couple, in a coupled state with the disposable fluid guide assembly 32, to the pneumatic channel openings 310 of the pneumatic channels 311 in order to apply overpressure or underpressure to the pneumatic channels 311.

[0512] In particular, each media dosing interface 768 is formed as an elongated, rectangular elevation having a rib-shaped contact surface 774 on its opposite longitudinal sides, against which the rib-shaped structure of the outer side of the sample receptacles 200, 204 can be supported in the coupled state. Consequently, in the coupled state, the disposable fluid guide assembly 32 is held securely in the pneumatic connection block 758.

[0513] In addition, the underside 760 of the pneumatic connection block 758 is equipped with a detection unit 653 in the form of a sensor unit 776, which is provided with several sensors 777.

[0514] The sensors 777 can be either sources and / or detectors that interact with corresponding sources and / or detectors in the sensor element blocks 652. In the coupled state, a beam path exists between the two, via which optical signals can be sent and received. The free exchange of optical signals is ensured by the sensor windows 306, 308, which allow a beam path perpendicular through the one-way fluid guide assembly 32 and provide optical access to other fluid channels adjacent to the sensor windows 306, 308 for the beam path.

[0515] In addition, the underside 760 is provided with alignment geometries, for example in the form of guide pins 780, with which the pneumatic connection block 758 can be aligned to the disposable fluid guide assembly 32.

[0516] In addition to the media dosing interfaces 768, a blood sample intake interface 784 is provided, which is shaped as a recess.

[0517] The blood sample containers 202 and 204 can engage in the recess to be supported in a way that prevents them from slipping.

[0518] The pneumatic connection block 758 is further coupled to a drive assembly 788 associated with the surface 30 of the sensor element 26 (see Fig. 35), which is designed for the linear displacement of the pneumatic connection block 758 and thus for the rapid fluidic coupling and decoupling and thus replacement of the disposable fluid guide assembly 32.

[0519] For this purpose, the drive assembly 788 has a drive, e.g., a crank 790, to which a spindle 792 is connected in a rotationally fixed manner. The spindle 792 passes through a threaded nut 796, which is attached to a drive block 798, which has a drive surface 800 on its underside for engagement with the pneumatic connection block 758.

[0520] The drive block 798 is guided linearly via rods 804 in the base block 662.

[0521] In order to put the protein defect diagnostic device 10 into operation, the sensor element holder 28 and thus the disposable fluid guide assembly 32 are first aligned by the centering unit 56.

[0522] When the disposable fluid guide assembly 32 is placed and pressed down, the two movably mounted media connection blocks 646 align with the disposable fluid guide assembly 32. Subsequently, by operating the crank 790, the pneumatic connection block 758 can be guided downward along the centering rods 804 toward the container 612 until the underside 760 of the pneumatic connection block 758 rests against the top side 288 of the disposable fluid guide assembly 32. The pneumatic connection block 758 also extends toward the disposable fluid guide assembly 32. This means that the entire device is aligned according to the position of the optical unit 34.

[0523] Overall, a positive connection is created between the media connection blocks 646 and the disposable fluid guide assembly 32, which is clamped between the media connection blocks 646 and the pneumatic connection block 758. The clamping achieves a fluid connection of the disposable fluid guide assembly 32 to the pneumatic connection block 758, as well as a fluidic connection between the media connection blocks 646 and the disposable fluid guide assembly 32.

[0524] Furthermore, the disposable fluid guide assembly 32, in particular the sensor element holder 28, is finally aligned in the beam path 42. The protein defect diagnostic device 10 is in an operational state, so that the surface 30 of the sensor element 26 can either be conditioned and / or brought into contact with a blood sample. Furthermore, an IR spectrum of the surface 30 of the sensor element 26 can now be recorded via the optical unit 34.

[0525] A hydraulically or purely electrically operated drive assembly 788 is also conceivable.

[0526] Fig. 37 shows a schematic flow diagram of the method steps for conditioning a sensor element for a protein defect diagnosis and for applying a blood sample to a sensor element for a protein defect diagnosis and for analyzing protein defects in a blood sample.

[0527] The procedural steps are explained in more detail below.

[0528] First, a sensor element is attached to the disposable fluid guide assembly such that the sensor element closes several interaction chambers on one side, wherein the sensor element has a surface to be treated which forms the previously open side of the interaction chamber (step S5).

[0529] Thereafter, a linker-containing conditioning fluid is introduced into the interaction chambers below a preconditioned surface on the sensor element to which at least one linker is bound, to which antibodies can specifically bind (step S6).

[0530] Next, the linker-containing conditioning fluid is passed out of the interaction chamber via the fluid channels (step S7).

[0531] Optionally, the interaction chamber can be rinsed with a rinsing fluid (step S8), which serves to clean and vent it.

[0532] Optionally, the interaction chamber can be in contact with a fluid until an antibody-containing conditioning fluid is introduced into the interaction chamber. The fluid can, for example, be a buffer fluid to prevent the interaction chamber from running dry. This can be achieved by leaving a residue of a fluid, e.g., a buffer fluid, in the interaction chamber after the respective process steps. This can then be displaced by the antibody-containing conditioning fluid, so that the interaction chamber is always kept moist.

[0533] Thereafter, the antibody-containing conditioning fluid is introduced into the interaction chamber below an antibody-conditioned surface on the sensor element to which at least one antibody is bound, to which a candidate biomarker can bind in a protein-specific and conformation-independent manner (step S9).

[0534] Optionally, the interaction chamber can be rinsed with a rinsing fluid after the previous step (step S10). Further steps can then be performed with other conditioning fluids to condition the surface of the sensor element.

[0535] Optionally, the interaction chamber can be in contact with a fluid until a blood sample is introduced into the interaction chamber. The fluid can also be a buffer fluid, for example, to prevent the interaction chamber from running dry. This can be achieved by leaving a residual fluid in the interaction chamber after the respective process steps. This can then be displaced by the blood sample, keeping the interaction chamber moist until the sample is applied.

[0536] Subsequently, the blood sample is introduced into the interaction chamber below a surface that is in a measurement-ready state (step S11).

[0537] Finally, the surface, which is in a ready-to-measure state, is irradiated with IR radiation below an IR spectrum (step S12).

[0538] In Fig. Figure 38 shows another schematic flow diagram of the process steps for analyzing protein defects in a blood sample. The individual process steps are explained in detail below.

[0539] In the first step, a conditioning fluid is passed from the first fluid channel through the interaction chamber into the second fluid channel (step S13).

[0540] Subsequently, the conditioning fluid is returned along the second fluid channel through the interaction chamber into the first fluid channel (step S14).

[0541] Steps S13 and S14 may be repeated for a predetermined period of time or until a predetermined number of cycles is reached.

[0542] Subsequently, a blood sample can be passed along a first flow direction from a first sample receptacle through the interaction chamber into the second blood sample receptacle (step S15).

[0543] Optionally, the fluid flow of the blood sample can be measured along the first flow direction, whereby upon detection of an air front or an irregularity in the fluid flow, a flow reversal opposite to the first flow direction is initiated.

[0544] Thereafter, the blood sample can be guided along a second flow direction, which is opposite to the first flow direction, from the second sample receptacle through the interaction chamber into the first sample receptacle S16.

[0545] Optionally, the fluid flow of the blood sample can be measured along the second flow direction, whereby upon detection of an air front or an irregularity in the fluid flow, a flow reversal opposite to the second flow direction is initiated. Preferably, the flow reversal is initiated when the respective container from which the fluid flow originates is completely empty. This can be determined in particular by detecting the air front, as this means that the respective fluid-transporting container is completely empty. This ensures particularly precise control of the fluid flow. By initiating the flow reversal, it is advantageously possible to prevent air bubbles from entering the interaction chamber right from the initial filling stage.

[0546] Steps S15 and S16 may be repeated for a predetermined number of cycles or for a predetermined period of time.

[0547] Finally, the surface of the sensor element is irradiated with IR radiation to obtain an IR spectrum (step S17).

[0548] Optionally, steps S15 and S16 may be performed during step S17.

[0549] In particular, during at least one of the steps S15 - S17, the surface of the sensor element can be tempered, in particular to room temperature.

[0550] Also, during at least one of the steps S15 - S17, preferably all steps S15 - S17, the surface of the sensor element can be tempered, in particular to room temperature. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 2020 / 0 141 866 A1

[0008]

Claims

[1] Microfluidic device (12) for applying a blood sample to a sensor element (26) for a protein defect diagnosis and / or for conditioning a sensor element (26) for a protein defect diagnosis, comprising at least one interaction chamber (24) which is partially closed by a sensor element (26), wherein a first fluid channel (74) opens at one end (66) of the at least one interaction chamber (24) and a second fluid channel (78) opens at the opposite end (70), a first media dosing unit (16) for conditioning fluid (96), which is optionally fluidically connected to the first fluid channel (74) at one end (66) of the at least one interaction chamber (24) via at least one valve (76), a second media dosing unit (18) for conditioning fluid (96), which is optionally fluidically connected to the second fluid channel (78) at an opposite end (70) of the at least one interaction chamber (24) via at least one valve (80), wherein, alternatively or in addition to the first and second media dosing units (16, 18), at least one first blood sample receptacle (20) which merges into a first sample channel (188) and an associated first fluid channel (74), and at least one second blood sample receptacle (22) which merges into a second sample channel (194) and the associated second fluid channel (78), so that each interaction chamber (24) is fluidically connectable only to its own first and second blood sample receptacles (20, 22), and a pneumatic unit (14) connected to the first and second media dosing units (16, 18) and / or the first and second blood sample receptacles (20, 22) and configured to alternately apply positive pressure and negative pressure or positive pressure and ambient pressure to them and to pump conditioning fluid (96) and / or the blood sample (212) back and forth through the at least one interaction chamber (24). [2] Microfluidic device (12) according to claim 1, characterized by that a detection unit (653) is provided which monitors the fluid flow in a contactless manner adjacent to the ends (66, 70) of the interaction chamber (24). [3] Microfluidic device (12) according to claim 2, characterized by that the detection unit (653) is designed to detect the occurrence of air bubbles in a fluid channel, and wherein a control (48) is provided which brings about a flow reversal when an air bubble occurs. [4] Microfluidic device (12) according to one of the preceding claims, characterized by that a disposable fluid guide assembly (32) is provided which has the interaction chamber (24), fluid channels or sections of the fluid channels and valves and to which the sensor element (26) is attached and to which the media dosing units (16, 18) can be reversibly coupled and / or into which one or more blood samples (212) can be fluidically introduced, in particular wherein the disposable fluid guide assembly (32) has sensor windows (306, 308) which lead adjacent to the opposite ends (66, 70) up to close to the fluid channels and via which the detection unit (653) is visually coupled to the interior of the fluid channels. [5] Microfluidic device (12) according to claim 4, characterized byin that the disposable fluid guide assembly (32) has a plurality of interaction chambers (24) which have a common sensor element (26) and which each have their own first and second fluid channels (76, 78) at their ends (66, 70). [6] Microfluidic device (12) according to claim 5, characterized by a plurality of storage containers (94, 118) for conditioning fluids (96), which are fluidly connected to the interaction chambers (24) via fluid lines (100, 128), wherein the pneumatic unit (14) is provided with a plurality of drive valves (104) via which the storage containers (94, 118) can be alternately subjected to overpressure and underpressure or to overpressure and ambient pressure in order to pump the medium (96) back and forth between the storage containers (94, 118) and through the interaction chambers (24). [7] Microfluidic device (12) according to one of claims 4 to 6, characterized bythat the pneumatic unit (14) can be reversibly coupled to the disposable fluid guide assembly (32), in particular by arranging the disposable fluid guide assembly (32) between the pneumatic unit (14) and the media dosing units (16, 18). [8] Microfluidic device (12) according to claim 6 or 7, insofar as claim 7 is dependent on claim 6, characterized by that the first media dosing unit (16) has a plurality of first storage containers (94) for conditioning fluids (96) and the second media dosing unit (18) has a plurality of second storage containers (118) for conditioning fluids (96), wherein from each of the plurality of first storage containers (94) extends a fluid channel serving as a media channel (88), which can be reversibly coupled via at least one media valve (90) selectively to groups of first fluid channels (74) or to all first fluid channels (74), and wherein from each of the plurality of second storage containers (118) extends a fluid channel serving as a media channel (122), which can be reversibly coupled via at least one media valve (126) selectively to groups of second fluid channels or to all second fluid channels, in particular wherein each media channel (122) is provided with its own media valve (126). [9] Microfluidic device (12) according to claim 8, characterized by that the media channels (88) of the first media metering unit (16) combine to form a common media collection channel (112) which can be reversibly coupled to at least one central media connection (114) on the disposable fluid guide assembly (32), and / or that the media channels (122) of the second media metering unit (18) combine to form a common media collection channel (140) which can be selectively connected to groups of or all of the second fluid channels (78) via valves. [10] Microfluidic device (12) according to claim 9, characterized by that at least one disposal channel (170) provided with an outlet valve (172) branches off from the at least one common media collection channel (112), which opens into a disposal container (174) for waste medium. [11] Microfluidic device (12) according to one of claims 8 to 10, characterized bythat at least one drive valve (104) is assigned to the plurality of first storage containers (94) for conditioning fluids (96), and at least one drive valve (132) is assigned to the plurality of second storage containers (118) for conditioning fluids (96), in order to subject each storage container (94, 118) of the plurality of first and second storage containers (94, 118) for conditioning fluids (96) to overpressure and underpressure or to overpressure and ambient pressure via its assigned drive valve (104, 132), in particular wherein the drive valves (104, 132) of the assigned interaction chamber (24) are alternately controlled such that one storage container (94, 118) is subjected to overpressure and the other to underpressure or ambient pressure. [12] Microfluidic device (12) according to one of the preceding claims, characterized byin that the microfluidic device has a plurality of interaction chambers (24) and a first blood sample receptacle (20) with a group of first blood sample receptacle containers (200), which merge into the associated first fluid channels (74) via first sample channels (188), and a second blood sample receptacle (22) with a group of second blood sample receptacle containers (204), which merge into the associated second fluid channels (78) via second sample channels (194), so that each interaction chamber (24) is only fluidically connectable to its own first and second blood sample receptacle containers (200, 204). [13] Microfluidic device (12) according to claim 12, characterized by that each sample channel (188, 194) is provided with its own shut-off valve (190, 196) in order to pump the blood sample (212) to the interaction chamber (24) when the valve (190, 196) is open. [14] Microfluidic device (12) according to claim 13, characterized byin that the plurality of first blood sample containers (200) and the plurality of second blood sample containers (204) are each assigned a separate connection to the pneumatic unit (14), which can be switched via at least one control valve (208, 210) such that each blood sample container (200, 204) can be subjected to overpressure and underpressure or to overpressure and ambient pressure via the at least one control valve (200, 204), in particular wherein the blood sample containers (200, 204) of an interaction chamber (24) are alternately controlled such that one blood sample container (200, 204) is subjected to overpressure and the other (200, 204) is subjected to underpressure or ambient pressure, and the blood sample (212) is pumped back and forth via the sensor element (26). [15] Microfluidic device (12) according to claim 14, characterized byin that each of the plurality of first and / or second blood sample receptacles (200, 204) is provided with a membrane element (368) or a lid in order to cover a sample inlet (366) on the blood sample receptacle (200, 204) in a liquid-tight, resealable manner, wherein the membrane element (368) is designed in particular as a hydrophobic, gas-permeable membrane film which can be reversibly coupled to the at least one control valve (208, 210) assigned to the blood sample receptacle in order to subject the blood sample receptacle to overpressure and underpressure or to overpressure and ambient pressure via the membrane element. [16] A protein defect diagnostic device (10) comprising a microfluidic device (12) according to any one of claims 1 to 15, wherein the protein defect diagnostic device (10) comprises a sensor element (26) which closes at least one, in particular several or all of the interaction chambers (24) with its surface-treated upper side (30) on the underside, and an optical unit (34) which has an IR source (36), an IR detector (38) and a beam path (42) connecting the IR source (36) and the IR detector (38) through the one or more interaction chambers (24), wherein the optical unit (34) is configured to guide the IR radiation generated by the IR source (36) via the sensor element (26) to the IR detector (38) via the beam path (42) in order to record an IR spectrum from the surface (30) of the sensor element (26). [17] A method for applying a blood sample to a sensor element (26) for a protein defect diagnosis and / or for conditioning a sensor element (26) for a protein defect diagnosis, with a microfluidic device (12) according to one of claims 1 to 15, wherein the method comprises a cycle with the following steps: a) passing a blood sample (212) or a conditioning fluid (96) from the first fluid channel (74) through the interaction chamber (24) into the second fluid channel (78); and b) Returning the blood sample (212) or the conditioning fluid (96) along the second fluid channel (78) through the interaction chamber (24) into the first fluid channel (74). [18] Method according to claim 17, characterized by the following step: c) Repeating steps a) and b) for a predetermined period of time or until a predetermined number of cycles is reached. [19] Method according to claim 17 or 18, characterized byDetecting whether a fluid front has passed a specific section in the flow path and then reversing the flow direction. [20] A method for analyzing protein defects in a blood sample, comprising a protein defect diagnostic device according to claim 16, characterized by that the procedure includes the following steps: a) guiding a blood sample (212) along a first flow direction from a first blood sample receptacle (20) through the interaction chamber (24) into a second blood sample receptacle (22); b) returning the blood sample (212) along a second flow direction, which is opposite to the first flow direction, from the second blood sample receptacle (22) through the interaction chamber (24) into the first blood sample receptacle (20); and c) irradiating the surface (30) of the sensor element (26) with IR radiation to obtain an IR spectrum.

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