Reaction chamber unit and microfluidic test carrier

Abstract

The invention relates to a reaction chamber unit (28) for a microfluidic test carrier (10). The reaction chamber unit (28) comprises: a reaction chamber (114) which comprises at least one reaction chamber channel structure (120); a fluid inlet (116) through which a fluid can flow into the reaction chamber (114); and a gas outlet (118) through which a gas can escape from the reaction chamber (114), wherein the reaction chamber (114) is delimited by a base surface (140) and by a side surface (142) adjoining the base surface (140). The reaction chamber (114) comprises at least a first reaction chamber depth (144) and a second reaction chamber depth (146) which differs from the first reaction chamber depth (144). The invention also relates to a microfluidic test carrier (10) comprising the reaction chamber unit (28).

Description

[0001]- 1 - Orphan Diagnostics AS Reaction Chamber Unit and Microfluidic Test Carrier The invention relates to a reaction chamber unit for a microfluidic test carrier and to a microfluidic test carrier comprising the reaction chamber unit. Microfluidics deals with the behavior of fluids, such as liquids and gases, in structures that have a size in the micro range. The micro range is defined as structures with a size of greater than or equal to 1 µm (micrometer) to less than or equal to 1 mm (millimeter). The use of structures in the micro range makes it possible to handle the smallest fluid volumes, such as a few microliters. This is advantageous when the components of very small sample volumes need to be analyzed, for example in the diagnostics of human or animal fluids such as blood, saliva, or urine.The use of extremely small sample volumes is used, among other things, in rapid diagnostic test systems, in which the sample is reacted with special test substances, and the test result can be read within minutes using special analytical techniques. Known rapid test systems, for example, are based on an enzymatically controlled reaction between the sample and the test substance with a visually detectable color change. Known rapid diagnostic test systems, for example, include microfluidic channel structures, by means of which fluids can be specifically transported and mixed with each other. The transport of a fluid along the microfluidic channel structure is based on various physical principles. The transport of the fluid can, for example, occur passively through capillary forces prevailing in the channel structures.External drive mechanisms, such as pumps or centrifugal forces, can also be used to move the fluid within the channel structures. To initiate the reaction, the sample fluid and the test substance are mixed together to cause them to react. Due to the small distance between the walls of the microfluidic channel structures, the fluid flow within the microfluidic channel structures is laminar, i.e., non-turbulent, so the mixing of two fluids is in no way comparable to macroscopic systems. Therefore, the special behavior of fluids within microfluidic channels must be considered when designing microfluidic test systems.For example, if the reaction takes place within microfluidic structures, special mixing structures are required to ensure thorough mixing of the sample fluid and test substance, thus ensuring a complete reaction. Rapid diagnostic test systems are of particular interest. These systems are designed to be easy to handle, require minimal equipment, and enable reliable test evaluation within a short period of time (less than a minute). Rapid test systems can be deployed in any mobile manner, regardless of whether an analysis laboratory, a power supply, or specially trained operators are available. Consequently, with the help of rapid diagnostic test systems, diseases can be detected more quickly, and patients can be promptly provided with targeted treatment.Areas of application for rapid diagnostic test systems include emergency medicine, outpatient clinics, and economically poorer regions. Methanol poisoning, for example, is an easily treatable condition if recognized early. Methanol poisoning occurs predominantly in less developed countries, where methanol is added to ethanol, the "regular alcohol," as a cheap substitute to increase profit margins. Methanol is metabolized in the body to formic acid and inhibits mitochondrial respiration, causing intracellular hypoxia, which leads to hypoxia at the cellular level and subsequently to metabolic acidosis. Therefore, untreated methanol poisoning can lead to visual disturbances, including blindness, brain damage, or even death. The methanol level in the blood can be tested using chromatographic methods.These methods are reliable, but require stationary laboratory equipment and a qualified operator. Both are usually not readily available in less developed countries. Another disadvantage is that methanol levels can be negative in the late stages, when all the methanol has been metabolized to formic acid. Other indirect detection methods that utilize osmolality and anion gaps are rather nonspecific, and the necessary technical equipment is also lacking in less developed countries. These disadvantages were recognized with the invention, and targeted work was carried out on solutions for mobile rapid diagnostic test systems to reliably detect diseases such as methanol poisoning on-site, quickly, and without complex, expensive, and heavy laboratory equipment.Furthermore, the invention makes it possible to enzymatically detect formic acid VEL-20396-P-WO - 3 - Orphan Diagnostics AS, which is produced by the metabolism of methanol. In this way, the detection of methanol poisoning is also possible in later stages. The invention is therefore based on the object of providing a microfluidic structure for analyzing a sample in a rapid diagnostic test system, which enables rapid reaction control and meaningful detection of a substance to be detected in the sample. This object is achieved according to the invention by a reaction chamber unit and a microfluidic test carrier, as described herein and defined in the claims. According to one aspect, the microfluidic test carrier comprises a test carrier base element, a first microfluidic test carrier channel structure arranged in the test carrier base element, and a movement element.According to this aspect, the movement element comprises at least one microfluidic movement element channel structure, wherein the movement element channel structure comprises an inlet opening and an outlet opening. According to this aspect, the movement element is movable relative to the test carrier base element between a first position and a second position. According to this aspect, in the first position of the movement element, the inlet opening of the movement element channel structure is in fluid communication with the first test carrier channel structure. According to this aspect, in the second position of the movement element, fluid communication between the movement element channel structure and the first test carrier channel structure is interrupted. The microfluidic test carrier thus comprises a specifically movable element—the movement element—which can be configured to move a defined sample volume.The defined sample volume can be present in the movement element channel structure between the inlet opening and the outlet opening. The movement element thus makes it possible to measure a defined sample volume and transport it by means of a mechanical movement. A mechanical movement is understood to be a movement of the fluid without a fluid flow, in which, for example, the fluid does not move relative to the movement element channel structure. The defined sample volume can be used for a detection reaction, for example for the enzymatic detection of formic acid and / or a methanol content in the blood. Due to the defined sample volume, the result of the detection reaction can be improved compared to a detection reaction with an unknown sample volume. VEL-20396-P-WO - 4 - Orphan Diagnostics AS A qualitative statement can also be made about the content of a substance to be detected in the defined sample volume.Consequently, the microfluidic test carrier enables high sensitivity and specificity with regard to the detection of a substance in a defined sample volume. In one embodiment, the inlet opening differs from the outlet opening. For example, the inlet opening and the outlet opening are arranged at opposite ends of the moving element channel structure. In an alternative embodiment, the moving element channel structure can have an opening that is configured both as an inlet opening and as an outlet opening. The first test carrier channel structure comprises, for example, a sample-receiving test carrier channel structure that is configured to receive a sample and guide it to the moving element channel structure. The sample is preferably conveyed by means of capillary force, in particular exclusively by means of capillary force, i.e.without the application of external forces, such as those exerted by pumps or pressure-generating systems. The sample received by the sample-receiving test carrier channel structure can flow, for example by capillary force, into the moving element channel structure. The first test carrier channel structure can alternatively or additionally comprise a ventilation channel which, in the first position of the moving element, is in fluid communication with the moving element channel structure. A sample receptacle arranged in the test carrier base element can be in fluid communication with the first test carrier channel structure. An operator or a pipetting device can, for example, apply a sample to the sample receptacle. In the first position of the moving element, the inlet opening and / or the outlet opening of the moving element channel structure and a section of the first test carrier channel structure can be aligned.The inlet opening and the outlet opening of the moving element channel structure are preferably in fluid communication with one another and are connected, for example, directly by a microfluidic channel of the moving element channel structure. The inlet opening and the outlet opening of the moving element can be arranged at opposite ends of the microfluidic channel of the moving element channel structure. In the second position of the moving element, the moving element can close the first test carrier channel structure. The first test carrier channel structure is closed, for example, by means of a positive connection between the moving element and the test carrier base element. The first test carrier channel structure can be closed or even sealed by means of the moving element. The movement of the moving element is preferably carried out manually by the operator.In an alternative embodiment, the movement of the movement element can be automated. Automated movement of the movement element can be performed, for example, by a medical device configured to receive the microfluidic test carrier. In some embodiments, the microfluidic test carrier can comprise a second test carrier channel structure. In the second position of the movement element, the movement element channel structure can be in fluid communication with the second test carrier channel structure. The second test carrier channel structure can be arranged in the test carrier base element. In the second position of the movement element, the outlet opening and / or the inlet opening of the movement element channel structure can be aligned with a portion of the second test carrier channel structure.The second test carrier channel structure comprises, for example, a fluid-storing test carrier channel structure configured to store a fluid, e.g., a dilution solution, and to conduct it to the moving element channel structure. When the moving element is in the second position, the fluid-storing test carrier channel structure can be in fluid communication with the moving element channel structure such that a fluid stored in the fluid-storing test carrier channel structure can flow into the moving element channel structure and displace and dilute a fluid located in the moving element channel structure. By means of the fluid-storing test carrier channel structure, for example, a 20-fold to 50-fold dilution of the fluid present in the moving element channel structure can be achieved. The fluid-storing test carrier channel structure will be defined in more detail later.VEL-20396-P-WO - 6 - Orphan Diagnostics AS The second test carrier channel structure can further comprise a channel section which, in the second position of the movement element, is aligned with the outlet opening of the movement element channel structure such that fluid can flow from the movement element channel structure into this channel section. In this way, for example, fluid present in the movement element channel structure can be guided into the channel section by means of the dilution solution. Capillary forces prevailing in the channel section can serve as a transport force for the dilution solution and the fluid. Alternatively or additionally, pressure can be exerted on the dilution solution such that the dilution solution pushes the fluid out of the movement element channel structure. It is understood that the fluid present in the movement element channel structure can at least partially mix with the dilution solution.The dilution solution can thus dilute the fluid. The fluid can, for example, comprise a human or animal fluid, such as blood, saliva, urine, tissue fluid, eye fluid, cerebrospinal fluid, etc. The second test carrier channel structure can further comprise a mixing structure that is in fluid communication with the moving element channel structure when the moving element is in the second position. The mixing structure can adjoin the channel section or comprise the channel section and directly adjoin the outlet opening of the moving element channel structure. The mixing structure can be configured to ensure good mixing of the dilution solution in the fluid-storing test carrier channel structure and the fluid in the moving element channel structure.A preferred flow direction of fluid is from the fluid-storing test carrier channel structure to the movement element channel structure and further to the channel section and optionally to the mixing structure. The second test carrier channel structure is designed, for example, as a microfluidic test carrier channel structure. The second test carrier channel structure further comprises, for example, a gas outlet that allows gas, e.g., air, to escape. Alternatively or additionally, the second test carrier channel structure can be in fluid communication with a vent when the movement element is in the second position. For example, the channel section is in fluid communication with the gas outlet so that gas can escape from it when fluid (e.g., a fluid present in the movement element channel structure and / or the dilution solution) flows into it.VEL-20396-P-WO - 7 - Orphan Diagnostics AS The moving element channel structure can be configured to receive a fluid volume in the first position and to discharge this fluid volume in the second position. In other words, the moving element can be configured such that when the moving element is moved from the first to the second position and / or the second to the first position, a fluid volume located in the moving element channel structure is moved together with the moving element. A fluid can be introduced into the moving element channel structure in the first position by means of the first test carrier channel structure and can be conveyed out of the moving element channel structure in the second position by means of the second test carrier channel structure. The moving element channel structure can provide a channel with a defined volume between the inlet opening and the outlet opening.The channel can be moved from the first to the second position upon movement of the moving element. A fluid volume present in the channel is, for example, moved together with the channel. The absorbed and released fluid volumes are, for example, identical, apart from minimal fluid adhesion to channel walls of the moving element channel structure. In some embodiments, a width of the moving element in the region of the moving element channel structure can be greater than a width of the moving element adjacent to the moving element channel structure. This design prevents fluid from creeping out of the moving element channel structure or at least reduces the amount of creeping fluid. Preferably, the moving element channel structure defines a width and a height of the moving element that is greater than a width and a height of the region adjacent to the moving element channel structure.The region adjacent to the moving element channel structure can extend from the moving element channel structure such that it is indented relative to the outer edges of the moving element channel structure. In this way, fluid creepage is also prevented or at least reduced. Preferably, the region adjacent to the moving element channel structure with a smaller width and / or height is arranged between the first test carrier channel structure and the second test carrier channel structure when the moving element is in the first position. Preferably, the region adjacent to the VEL-20396-P-WO - 8 - Orphan Diagnostics AS moving element channel structure with a smaller width and / or height does not contact either the first or the second test carrier channel structure. Thus, fluid creeping into the addressed region cannot clog or contaminate the first and second test carrier channel structures.The region adjacent to the moving element channel structure with a smaller width and / or height can adjoin a wall of the moving element channel structure that delimits the fluid-absorbing channel. Furthermore, the moving element can be received or receivable in a receiving region of the test carrier base element such that the inlet opening of the moving element channel structure and the outlet opening of the moving element channel structure directly contact a respective boundary surface of the receiving region. The direct contact between the inlet opening and / or the outlet opening and the respective boundary surface makes it possible to close the inlet opening and / or the outlet opening in a respective position of the moving element. The moving element can be inserted or insertable in a form-fitting manner into the test carrier base element, in particular the receiving region. The moving element can be removable from the test carrier base element.Inserting and / or removing the movement element is possible, for example, if the test carrier base element is not covered. A cover film can close the channel structures of the microfluidic test carrier. Furthermore, a cavity can be provided between the movement element and at least one of the boundary surfaces of the receiving area, which cavity adjoins the movement element channel structure when the movement element is inserted into the test carrier base element. Preferably, the cavity adjoining the movement element channel structure is provided between the movement element and all adjacent boundary surfaces of the receiving area. The boundary surfaces can, for example, comprise a lower boundary surface, an upper boundary surface, two walls, and two end surfaces, wherein the walls and the end surfaces connect the lower and upper boundary surfaces.The cover film can also be a boundary surface of the receiving area. VEL-20396-P-WO - 9 - Orphan Diagnostics AS The cavity is preferably arranged such that, when the movement element is in the first position, the second test carrier channel structure opens into the cavity. For example, one channel section or two channel sections of the second test carrier channel structure open into the cavity when the movement element is in the first position. If a microfluidic channel opens into the cavity with a sharp-edged transition, e.g. with an acute angle, between the microfluidic channel and the cavity, then this structure causes a fluid stop, i.e. the surface tension of the fluid in the microfluidic channel prevents the fluid from flowing into the cavity. Furthermore, the cavity can serve as leak protection for the movement element channel structure.If fluid were to creep over the edges of the moving element channel structure, it would be stopped at the transition to the cavity. The width of the moving element in the region of the moving element channel structure is greater than the width of the moving element adjacent to the moving element channel structure. In this way, the cavity can be formed. In an alternative embodiment, the width of the receiving area for the moving element adjacent to the moving element channel structure is widened when the moving element is in the first position. The receiving area can form two stops that limit the movement of the moving element such that the moving element is in the first position when it strikes the first stop and in the second position when it strikes the second stop. A projection projecting into the receiving area for the moving element can serve as the first stop.An end face of the receiving area can serve as a second stop. In some embodiments, the microfluidic test carrier can further comprise an operating element that is connected to the movement element such that it is configured to move the movement element between the first and the second position. The operating element can protrude beyond the test carrier base element or can be exposed such that an operator can actuate it, e.g., grasp it. The operating element is preferably moved manually by the operator. The operating element is, for example, graspable by the operator. Further alternative embodiments can be provided. For example, the VEL-20396-P-WO - 10 - Orphan Diagnostics AS operating element can protrude laterally. According to a further alternative embodiment, the operating element can protrude from the base or the lid of the test carrier base element.According to a further alternative embodiment, the test carrier base element can be recessed such that a part of the operating element and / or the movement element is grippable. For some applications, it can be advantageous for the operating element to protrude from the test carrier base element and to have an operating element projection that is connected or connectable to a locking element that prevents movement of the movement element from the first to the second or from the second to the first position. The locking element can be secured relative to the test carrier base element. In the secured state, the operating element is rigid, i.e., fixed relative to the test carrier base element. The locking element can thus prevent unintentional operation of the movement element, for example, during transport of the microfluidic test carrier.The microfluidic test carrier can have a gripping area in which no fluid structures are arranged, so that an operator can grip the microfluidic test carrier with their fingers. In some embodiments, the moving element channel structure can have a channel length that is between 0.5 mm and 10 mm, preferably between 2 mm and 8 mm, more preferably between 3 mm and 5 mm. Furthermore, the moving element channel structure, the first test carrier channel structure and / or the second test carrier channel structure can have a channel depth and / or channel width that is between 100 µm and 1000 µm, preferably between 300 µm and 800 µm, more preferably between 400 µm and 600 µm. In one embodiment, the channel length of the moving element channel structure is 4 mm, the channel depth is 500 µm and / or the channel width is 500 µm. The dimensioning of the moving element channel structure defines the prevailing physical forces, e.g.the capillary force, and the absorbable fluid volume. A volume absorption in the movement element channel structure between 0.2 µl and 10 µl, preferably between 0.5 µl and 5 µl, more preferably between 0.8 µl and 3 µl, can be provided. In an exemplary embodiment, the fluid volume that can be absorbed by the movement element channel structure is 1 µl. VEL-20396-P-WO - 11 - Orphan Diagnostics AS In some embodiments, a thickness of the movement element can be at least 5%, preferably at least 10%, more preferably at least 15% deeper than the channel depth of the movement element channel structure. Preferably, a surface delimiting the movement element channel structure is arranged at an acute angle or right angle to at least one of the outer surfaces of the movement element. In this way, a defined fluid stop can be achieved at the delimiting surfaces. The outer surface can comprise a bottom surface, a top surface and two side surfaces.An acute angle is understood to be an angle that is greater than 80° and less than or equal to 90°, preferably between 83° and 87°, and more preferably approximately 85°. In some embodiments, the microfluidic test carrier further comprises a venting structure arranged in the test carrier base element, which venting structure can be in fluid communication with the movement element and / or the second test carrier channel structure. According to one embodiment, the venting structure can be in fluid communication with the second test carrier channel structure only in the second position of the movement element. The fluid communication can be interrupted in the first position of the movement element. Furthermore, the venting structure can be arranged in the test carrier base element such that a gas volume displaced by moving the movement element from the first to the second position flows into the venting structure.Preferably, the ventilation structure is arranged in the movement element such that fluid communication exists between the second test carrier channel structure and the ventilation structure when the movement element is in the second position. Alternatively or additionally, fluid communication between the ventilation structure and the second test carrier channel structure can be interrupted when the movement element is in the first position. For some applications, it can be advantageous if fluid movement into and out of the movement element channel structure is based, preferably exclusively, on fluid transport by means of VEL-20396-P-WO - 12 - Orphan Diagnostics AS capillary force and / or by means of a suction force, e.g. by means of an absorbent fleece, and / or by means of air pressure.The microfluidic channel structures can be manufactured using milling and / or injection molding and / or additive manufacturing methods. Additive manufacturing methods encompass all manufacturing processes in which components are produced layer by layer based on three-dimensional models, e.g., 3D printing processes using a powder-bed melting process, free-jet material deposition, free-jet binder deposition, material deposition with directed energy input, material extrusion, bath-based photopolymerization, or layer lamination. The fluidic channel structures of the test carrier can be hydrophilized to improve fluid flow. Hydrophilizing a surface reduces its surface tension. One aspect concerns a fluid-storing test carrier channel structure.This may be the fluid-storing test carrier channel structure described above, which is implemented in the microfluidic test carrier. The fluid-storing test carrier channel structure can therefore be understood as a standalone aspect. Furthermore, the fluid-storing test carrier channel structure can be suitable for use with a microfluidic test carrier, for example, the microfluidic test carrier described above. In some embodiments, the fluid-storing test carrier channel structure can cooperate with the movement element, which is movable into the first position and the second position. The fluid-storing test carrier channel structure is described in more detail below.The fluid-storing test carrier channel structure for a microfluidic test carrier, for example the microfluidic test carrier described above, comprises, according to one aspect, a storage section for storing fluid, a fluid outlet in fluid communication with the storage section, and a gas inlet in fluid communication with the storage section, which is arranged at an end of the fluid-storing test carrier channel structure opposite the fluid outlet. For example, the fluid outlet is configured to allow fluid present in the fluid-storing test carrier channel structure to flow out. By means of the gas inlet, a gas volume can flow into the fluid-storing test carrier channel structure that corresponds to the fluid volume escaping through the fluid outlet.VEL-20396-P-WO - 13 - Orphan Diagnostics AS The fluid-storing test carrier channel structure is designed, for example, as a microfluidic test carrier channel structure. The fluid-storing test carrier channel structure provides a possibility for storing a fluid. This fluid can be used to dilute a sample solution. Storing fluid simplifies handling for the operator, as the operator has to perform fewer operating steps, i.e., adding the stored fluid is no longer necessary. The step of adding the stored fluid, e.g., a dilution solution, is no longer necessary. Furthermore, the fluid-storing test carrier channel structure increases the reliability of a microfluidic test carrier, as this prevents operating errors caused by the addition of fluid. It is understood that the fluid-storing test carrier channel structure reduces the overall duration of a detection test, as the manual addition of the stored fluid is no longer necessary.In summary, the detection of a substance in a sample is simplified, shortened, and more reliable using the fluid-storing test carrier channel structure. Advantageously, the fluid-storing test carrier channel structure can comprise a section with a channel cross-sectional constriction, which is arranged adjacent to the fluid outlet of the fluid-storing test carrier channel structure. The section with a channel cross-sectional constriction can be arranged between the fluid outlet and the storage section. The section with a channel cross-sectional constriction can further be configured to store a fluid. A capillary force in the section with the channel cross-sectional constriction can draw a fluid, for example, a diluent solution, from the fluid-storing test carrier channel structure.Advantageously, the storage section has a larger channel cross-sectional area than the section with a channel cross-sectional constriction, for example, at least twice the channel cross-sectional area. For example, the storage section, preferably the storage section and the section with a channel cross-sectional constriction together, can be configured to accommodate a fluid volume between 20 µl and 300 µl, preferably between 20 µl and 150 µl, more preferably between 25 µl and 100 µl, and even more preferably between 40 µl and 120 µl. It is understood that the accommodated fluid volume can consist of a liquid or a mixture of a liquid and a gas.VEL-20396-P-WO - 14 - Orphan Diagnostics AS For some applications, it may be advantageous if the capillary force in the storage section is negligible compared to the capillary force in the section of the channel cross-sectional constriction and / or in the region of the fluid outlet. The capillary force in the storage section can be negligible if it is at least 10 times, better at least 20 times, even better at least 30 times, smaller than the capillary force in the storage section. The capillary force relates, for example, to the use of an aqueous solution. An aqueous solution, for example, has a dynamic viscosity of between 0.2 mPa*s and 25 mPa*s, preferably between 0.3 mPa*s and 15 mPa*s, more preferably between 0.5 mPa*s and 8 mPa*s. An aqueous solution includes, for example, water, blood, blood plasma, saliva, urine and / or other body fluids at temperatures between 10°C and 35°C.The fluid-storing test carrier channel structure can comprise an aqueous solution in which an anticoagulant, for example, heparin, citrate, or EDTA, is dissolved. In some embodiments, the storage section can have a meander shape, and the channel structure in the meander shape can have a channel width between 2 mm and 0.8 mm, preferably between 1.8 mm and 1 mm, more preferably between 1.6 mm and 1.2 mm. A channel width can extend between two side surfaces of the storage section. Additionally or alternatively, the storage section can have a channel depth between 1.9 mm and 0.7 mm, preferably between 1.7 mm and 0.9 mm, more preferably between 1.5 mm and 1.1 mm. According to an exemplary embodiment, the channel width of the storage section can be 1.4 mm and / or the channel depth of the storage section can be 1.25 mm.A channel depth can extend between a bottom surface of the storage section and a cover surface opposite the bottom surface, e.g., a cover film that closes the storage section. The bottom surface and the cover surface are connected, for example, by means of the side surfaces. In an alternative embodiment, the storage section can comprise a continuous storage space, wherein the continuous storage space has, for example, a storage space width between 9 mm and 28 mm, preferably between 12 mm and 24 mm, more preferably between 15 mm and 20 mm. Additionally or alternatively, the continuous storage space can have a storage space length between 3 mm and 22 mm, preferably between 6 mm and 19 mm, more preferably between 10 mm and 16 mm. According to an exemplary embodiment, the storage space width is, for example, 17 mm and the storage space length is 13.4 mm.The dimensions of the continuous storage space of the fluid-storing test carrier channel structure are preferably selected such that the capillary forces are greater than the surface tension. A storage space depth of the continuous storage space can be between 0.8 mm and 1.2 mm, preferably between 0.9 mm and 1.1 mm, more preferably 1 mm. A storage space depth can extend between a bottom surface of the storage space and a cover surface opposite the bottom surface, e.g., a cover film that closes the storage space. The bottom surface and the cover surface of the storage space are connected, for example, by means of side surfaces. It has proven advantageous if at least part of a surface of the storage section is coated with a diffusion-barrier layer.The part of the surface can, for example, comprise side surfaces delimiting the storage section and / or a base surface and / or a cover surface adjacent to the side surfaces. The diffusion-barrier layer can reduce the diffusion of gases, such as oxygen or carbon dioxide. For example, a plasma treatment of the surface with SiOx (silicon oxide) carried out under vacuum can be used to create the diffusion-barrier layer. The diffusion-barrier layer is preferably chemically inert. The fluid-storing test carrier channel structure can further be comprised by the microfluidic test carrier and arranged in the test carrier base element. The fluid-storing test carrier channel structure can have one or more of the features listed above.The microfluidic test carrier comprises a movement element arranged in the test carrier base element, which is movable into a first position and a second position. Furthermore, the microfluidic test carrier can comprise a gas-filled chamber having at least one boundary surface formed by the movement element. The gas-filled chamber is in fluid communication with the gas inlet of the fluid-storing test carrier channel structure. The movement of the movement element can be manual, wherein the first and second positions differ from one another. VEL-20396-P-WO - 16 - Orphan Diagnostics AS The fluid-storing test carrier channel structure can be configured to dilute a fluid sample accommodated in the microfluidic test carrier. The amount of fluid accommodated in the fluid-storing test carrier channel structure preferably enables a dilution of the fluid sample by 20 to 50 times.The gas-filled chamber can have an internal volume in the first position of the movement element, which can be reduced in the second position of the movement element such that the gas-filled chamber is not in fluid communication with the gas inlet. The internal volume of the gas-filled chamber can therefore be variable. The gas-filled chamber can be in fluid communication with the gas inlet when the movement element is in the first and / or second position. According to an alternative embodiment, the gas inlet can be closed in the first position and open in the second position. According to one embodiment, when the movement element is moved from the first to the second position, gas is displaced from the gas-filled chamber, thus generating an overpressure at the gas inlet of the fluid-storing test carrier channel structure.In other words, the movement element and the gas inlet can be arranged such that a gas volume of the gas-filled chamber is forced into the gas inlet when the movement element is moved from the first to the second position. By means of the gas volume thus moved, an overpressure can be generated at the gas inlet end of the fluid-storing test carrier channel structure. The overpressure supports, for example, the emptying of fluid stored in the fluid-storing test carrier channel structure. The fluid can be drained via the fluid outlet. In some embodiments, a gas distribution chamber can be arranged upstream of the gas inlet, the cross-sectional area of ​​which is at least 50%, preferably at least 100%, more preferably at least 150% larger than that of the gas inlet. One aspect relates to a fluid-bundling test carrier channel structure.The fluid-bundling test carrier channel structure can be understood as a stand-alone aspect. In some embodiments, the first test carrier channel structure of the microfluidic test carrier described above can comprise a fluid-bundling test carrier channel structure for bundling fluid in a fluid-bundling channel. When the moving element is in the first position, the fluid-bundling test carrier channel structure can be in fluid communication with the moving element channel structure such that a fluid present in the fluid-bundling test carrier channel structure can flow into the moving element channel structure. The fluid-bundling test carrier channel structure is described in more detail below. The fluid-bundling test carrier channel structure can be understood as a stand-alone aspect.The fluid-bundling test carrier channel structure may further be suitable for use in a microfluidic test carrier, for example, the microfluidic test carrier described above. According to one aspect, the fluid-bundling test carrier channel structure is configured to bundle fluid in a fluid-bundling channel. According to this aspect, the fluid-bundling test carrier channel structure comprises the fluid-bundling channel, a receiving chamber configured to receive a fluid, a first section with at least two parallel fluid channels originating from the receiving chamber, and a second section in which the at least two parallel fluid channels of the first section meet and form a further fluid channel whose cross-sectional area is smaller than that of the two parallel fluid channels of the first section combined.According to this aspect, the fluid-bundling channel is in fluid communication with the fluid channels of the first section and the second section. When absorbing a fluid into a microfluidic structure, it is desirable for this absorption to occur as efficiently, quickly, and free of air bubbles as possible. This is precisely what the fluid-bundling test carrier channel structure enables. The parallel fluid channels of the first section efficiently absorb any fluid adjoining them using capillary force and quickly transport it to the adjoining fluid channels. The targeted design of the cross-sectional areas of the fluid channels further ensures fast and air bubble-free transport of the fluid by means of the fluid-bundling test carrier channel structure. The flow direction of the fluid is preferably from the receiving chamber to the first section and then to the second section and further into the fluid-bundling channel.The fluid-bundling test carrier channel structure can be configured to draw fluid adjacent to the first section into the first section and subsequently into the second section by means of capillary force. VEL-20396-P-WO - 18 - Orphan Diagnostics AS Preferably, the cross-sectional area of ​​the fluid channel of the second section is larger than the cross-sectional area of ​​one of the fluid channels of the first section. In some embodiments, the first section can comprise four fluid channels connected in parallel, which originate from a common receiving chamber. In each case, two of the fluid channels connected in parallel can open into a respective further fluid channel of the second section, wherein each further fluid channel of the second section has a cross-sectional area that is smaller than the cross-sectional area of ​​two parallel fluid channels of the first section combined.For some applications, it may be advantageous if the fluid-bundling test carrier channel structure further comprises a third section with the fluid-bundling channel, into which the further fluid channel(s) of the second section open and whose cross-sectional area is larger than that of the fluid channel of the second section. Preferably, the cross-sectional area of ​​the fluid channel of the third section is smaller than that of two parallel fluid channels of the second section combined. In some embodiments, the fluid-bundling test carrier channel structure can further comprise an absorbent fleece. A fluid contacting the absorbent fleece is drawn into the absorbent fleece by capillary force, i.e. the absorbent fleece enables fluid transport through its capillary structure. The receiving chamber can be configured to receive the absorbent fleece.The absorbent fleece can be configured to absorb a blood sample and release blood plasma, wherein the erythrocytes of the blood are separated and remain in the absorbent fleece. Consequently, only blood plasma passes through the absorbent fleece and can be released to the adjoining first section of the fluid-bundling test carrier channel structure. Preferably, each fluid channel of the fluid channels of the first section has a cross-sectional area that is less than 0.2 mm² and greater than 0.1 mm², preferably less than 0.17 mm² and greater than 0.13 mm², more preferably 0.15 mm². Additionally or alternatively, the at least one further fluid channel of the second section has a cross-sectional area that is less than 0.25 mm² and greater than 0.15 mm², preferably less than 0.23 mm² and greater than 0.18 mm², more preferably 0.2 mm².VEL-20396-P-WO - 19 - Orphan Diagnostics AS Furthermore, the at least one fluid channel of the third section can have a cross-sectional area that is less than 0.3 mm² and greater than 0.2 mm², preferably less than 0.28 mm² and greater than 0.23 mm², more preferably 0.25 mm². In some embodiments, a channel depth of the receiving chamber and a channel depth of the fluid channels in the first, second and third sections is, for example, 0.5 mm. In one embodiment, in the first section, the channel depth is 0.5 mm and the channel width is 0.3 mm. Furthermore, in the second section, the channel depth can be 0.5 mm and the channel width is 0.4 mm. Furthermore, in the third section, the channel depth can be 0.5 mm and the channel width is 0.5 mm. Due to the aforementioned dimensions, particularly efficient fluid transport through the fluid-bundling test carrier channel structure can be achieved.Furthermore, the fluid-bundling test carrier channel structure can comprise a sample receptacle, wherein the sample receptacle and the receptacle chamber are in fluid communication such that fluid applied to the sample receptacle is drawn into the absorbent fleece arranged in the receptacle chamber. The receptacle chamber can be directly connected to the sample receptacle. The sample receptacle can be configured to receive a liquid sample, for example, body fluids such as blood, serum, urine, stool, or saliva, in pure or diluted form. According to one aspect of the invention, the fluid-bundling test carrier channel structure described above can be comprised by a microfluidic test carrier. The microfluidic test carrier comprises a test carrier base element and the fluid-bundling test carrier channel structure arranged in the test carrier base element.The fluid-bundling test carrier channel structure can be manufactured by milling and / or injection molding and / or additive manufacturing methods. The sample receptacle can be a recessed area in the test carrier base element. In some embodiments, the microfluidic test carrier comprises the movement element and the fluid-bundling test carrier channel structure. In this configuration, when the movement element is in the first position, the fluid-bundling test carrier channel structure can be in fluid communication with the movement element channel structure such that a fluid present in the fluid-bundling test carrier channel structure can flow into the movement element channel structure. One aspect relates to a reaction chamber unit. The reaction chamber unit can be understood as an independent aspect.In some embodiments, the second test carrier channel structure of the microfluidic test carrier described above can comprise the reaction chamber unit. For example, when the movement element is in the second position, the reaction chamber unit can be in fluid communication with the movement element channel structure such that a fluid located in the movement element channel structure can flow into the reaction chamber unit. According to one aspect, the reaction chamber unit for a microfluidic test carrier comprises a reaction chamber comprising at least one reaction chamber channel structure, a fluid inlet through which a fluid can flow into the reaction chamber, and a gas outlet through which a gas can escape from the reaction chamber. According to this aspect, the reaction chamber is delimited by a bottom surface and a side surface adjoining the bottom surface.Furthermore, according to this aspect, the reaction chamber comprises at least a first reaction chamber depth and a second reaction chamber depth that differs from the first reaction chamber depth. It is understood that any surface of the reaction chamber can be understood as the bottom surface. For example, when using the microfluidic test carrier, the bottom surface can face a substrate on which the microfluidic test carrier rests, or face away from the substrate. For example, two opposing surfaces can also interact to form the microfluidic structure of the reaction chamber. The reaction chamber unit enables the sample to be brought together with a detection reagent so that a substance contained in the sample can be reacted with the detection reagent. To this end, the reaction chamber enables a homogeneous distribution of sample and detection reagent as well as thorough mixing of the sample and detection reagent.In addition, the reaction chamber provides a measuring area that enables optical detection. For example, a reaction between the substance to be detected in the sample and a detection reagent leads to a color change, the intensity of which allows conclusions to be drawn about the concentration of the substance to be detected. The special structure of the reaction chamber with its two reaction chamber depths VEL-20396-P-WO - 21 - Orphan Diagnostics AS ensures that the reaction chamber is filled with fluid particularly quickly, improves the mixing of sample and detection reagent, and offers a large measuring field for optical detection. A cross-section through the reaction chamber can comprise a stepped profile with a deeper step, i.e. the first reaction chamber depth, and a shallower step, i.e. the second reaction chamber depth. The first reaction chamber depth can be greater than the second reaction chamber depth.The reaction chamber depth is defined as the distance between the bottom surface and a lid surface of the reaction chamber opposite the bottom surface. The reaction chamber can therefore comprise two stages, with the first stage having a greater reaction chamber depth than the second stage. The different reaction chamber depths allow two flows with different flow properties to be present in the reaction chamber. The reaction chamber channel structure can be designed as a microfluidic channel structure. The reaction chamber channel structure is surrounded, for example, by at least three walls and can be sealed by a lid film. The lateral surfaces of the reaction chamber channel structure can be completely enclosed, for example, by the walls and the lid film.The reaction chamber channel structure can be dimensioned such that fluid transport by capillary force along the reaction chamber channel structure is possible. Along its longitudinal extent, the reaction chamber channel structure has, for example, a constant cross-sectional area and / or a constant cross-sectional profile, e.g., as a rectangular microfluidic channel. The reaction chamber channel structure can be completely fillable with fluid. The different reaction chamber depths enable efficient and air-bubble-free filling of the reaction chamber. The gas outlet of the reaction chamber unit is configured such that a gas, such as air, can escape from the flow space when fluid enters the flow space via the fluid inlet.For some applications, it may be advantageous if a microfluidic channel structure extends from the bottom surface of the reaction chamber and projects into a flow space of the reaction chamber. The flow space can therefore also comprise two differing depths. The microfluidic channel structure comprises, for example, a reaction chamber channel which is arranged in a region of the first reaction chamber depth and whose channel depth is less than the first reaction chamber depth. A capillary force in the reaction chamber channel can draw a fluid along a length of the reaction chamber channel. The reaction chamber channel has, for example, a minimum length of 2 cm, preferably 4 cm, more preferably 6 cm.In some embodiments, a flow field can be provided in a partial region of the first reaction chamber depth and in the second reaction chamber depth, which flow field is in fluid communication with the microfluidic reaction chamber channel. This allows effective filling of the reaction chamber. For example, the reaction chamber can be filled in under one minute. The flow field has, for example, a constant depth. For example, the flow field has a depth that is less than the first reaction chamber depth. The flow field has, for example, a depth that corresponds to the second reaction chamber depth. The flow field can cover a continuous surface area, which can serve as a continuous measurement surface and enables a uniform measurement result. In one embodiment, the reaction chamber channel can have a capillary force that is greater than the capillary force of the flow field.The reaction chamber channel can be only partially enclosed by a wall, so that the reaction chamber channel and the flow field are directly adjacent to one another. The wall comprises, for example, the bottom surface and two side wall surfaces. The reaction chamber channel can have an opening along its longitudinal extent, by means of which fluid in the reaction chamber channel is in fluid communication with fluid in the flow field. In other words, the reaction chamber channel can not have a cover surface. The reaction chamber channel and the flow field are, for example, directly adjacent to one another, i.e. there is no demarcation between the reaction chamber channel and the flow field. VEL-20396-P-WO - 23 - Orphan Diagnostics AS Due to the above-mentioned features, for example, a fluid can enter the reaction chamber through the fluid inlet and flow in or along the reaction chamber channel by means of capillary force.The reaction chamber channel can be connected to the flow field. Consequently, the fluid located in the flow field can be in fluid communication with the fluid flowing in or along the reaction chamber channel. The flow of the fluid in the reaction chamber channel drives the fluid in the flow field to move in the flow field, corresponding to the movement of the fluid in the reaction chamber channel. It is understood that the fluid in the reaction chamber channel can mix with the fluid in the flow field. The microfluidic reaction chamber channel is dimensioned, for example, such that a fluid, for example an aqueous fluid (e.g., blood, blood serum, diluted blood, diluted blood serum, water, urine, etc.), can be moved in or along the reaction chamber channel with the aid of capillary forces. A fluid flows through the reaction chamber channel and / or the flow field, for example, with laminar flow.The depth of the flow field is, for example, between 100 µm and 500 µm, preferably between 150 µm and 400 µm, more preferably between 200 µm and 300 µm. These dimensions of the flow field enable a uniform fluid distribution within the flow field. Furthermore, the flow field has, for example, a continuous area of ​​between 70 mm² and 130 mm², preferably between 80 mm² and 120 mm², more preferably between 90 mm² and 110 mm². In this way, the flow field can have a sufficient area to form a measuring field, for example, for an optical measurement. According to one embodiment, the reaction chamber channel is designed as a meander with a rectangular cross-section. A longitudinal extension and / or a transverse extension can be between 2 mm and 20 mm, preferably between 5 mm and 18 mm, more preferably between 8 mm and 15 mm.For some applications, it may be advantageous if the depth of the reaction chamber channel is between 300 µm and 700 µm, preferably between 400 µm and 600 µm, more preferably between 450 µm and 550 µm. Alternatively or additionally, the width of the reaction chamber channel can be between 100 µm and 700 µm, preferably between 200 µm and 600 µm, more preferably between 300 µm and 550 µm. These dimensions allow sufficient capillary force to be achieved in the reaction chamber channel when using an aqueous fluid. According to one embodiment, the depth and width of the reaction chamber channel can be 500 µm, for example in a meandering structure of the reaction chamber channel running in series one behind the other.According to an alternative embodiment, the depth of the reaction chamber channel can be 500 µm and the width of the reaction chamber channel 300 µm, for example, when implementing two parallel-connected meander structures of the reaction chamber channel. In some embodiments, a first side surface portion of the at least one side surface, which connects the fluid inlet and the gas outlet, can have a projection that protrudes into the flow space and / or delimits it. The projection is arranged, for example, adjacent to the gas outlet. The projection can extend from the bottom surface to the cover surface of the flow space. The projection can extend between 0.5 mm and 1.5 mm, preferably between 0.7 mm and 1.3 mm, more preferably between 1.1 mm and 0.9 mm into the flow space.The projection can be configured to prevent fluid creeping along the first side surface portion from reaching the gas outlet. A boundary surface of the projection and the first side surface portion can be arranged at an acute angle. The acute angle is greater than 80° and less than or equal to 90°, preferably between 83° and 87°, and more preferably approximately 85°. The projection thus enables reliable filling of the reaction chamber with fluid. In some embodiments, the reaction chamber channel can run meandering, spiraling, circular, and / or semicircular within the flow space. The exemplary embodiments of the reaction chamber channel can enable a space-saving arrangement of the channel structure in the test carrier base element.Furthermore, a circular, semicircular, and / or spiral arrangement of the reaction chamber channel enables a homogeneous filling of a mostly round measuring field. A round measuring field has the advantage of being easily readable optically. For some applications, it can be advantageous if the gas outlet has a cross-sectional area that is smaller than the cross-sectional area of ​​the reaction chamber channel, preferably more than 50% smaller, more preferably more than 75% smaller. The gas outlet is, for example, a microfluidic channel VEL-20396-P-WO - 25 - Orphan Diagnostics AS with a width of 200 µm and / or a height of 200 µm. Due to the above dimensions, the gas outlet can serve as a fluid stop, i.e., the fluid stops at the gas outlet due to the different dimensions of the microfluidic gas outlet channel and the reaction chamber channel.Furthermore, the gas outlet can be connected to a venting chamber via a venting channel such that gas can flow from the gas outlet into the venting chamber. The venting chamber can, for example, be configured to receive gas escaping from the reaction chamber. Furthermore, the venting chamber can be configured to receive fluid from the reaction chamber that escapes from the gas outlet. If, for example, fluid escapes from the reaction chamber, it is absorbed by the venting chamber and does not flow out of the test carrier in an undesired or uncontrolled manner. This makes the test carrier safe for transport and prevents contamination. Preferably, a volume of the venting chamber is larger than a volume of the gas outlet, preferably more than 50% larger, preferably more than 100% larger, further preferably more than 200% larger.The venting chamber can further be in fluid communication with a venting chamber opening, wherein the venting chamber opening is configured such that a gas, e.g. air, can escape from the venting chamber via it. In this way, the venting chamber can accommodate gas and / or fluid escaping from the reaction chamber. For some applications, it can be advantageous if a microfluidic mixing structure is arranged upstream of the fluid inlet in the direction of flow, wherein the mixing structure comprises, for example, a microfluidic channel that has at least one bend in its longitudinal course. Preferably, the microfluidic channel of the mixing structure comprises a plurality of bends, for example a meander structure with a plurality of alternating bends. The mixing structure serves to supply fluid homogeneously into the reaction chamber.In some embodiments, exactly one fluidically connected reaction chamber channel structure can be arranged between the fluid inlet and the gas outlet of the reaction chamber. In other words, a fluid entering the reaction chamber via the fluid inlet flows completely into the one fluidically connected reaction chamber channel structure and can, for example, displace gas present in the reaction chamber channel structure. The reaction chamber channel structure can be structured such that all structures are arranged in series. Alternatively, in some embodiments, two or more reaction chamber channel structures can be arranged between the fluid inlet and the gas outlet of the reaction chamber, each having a fluidically connected channel structure. The two or more reaction chamber channel structures can be arranged in parallel, i.e.The fluid entering the reaction chamber is branched at least once. The two or more channel structures can open into a common gas outlet or into a respective gas outlet. The two or more channel structures can be supplied with fluid from a common fluid inlet. For example, the common fluid inlet can fork so that a channel structure opens into the reaction chamber from the common fluid inlet. The total volume of the reaction chamber can be between 20 µl and 200 µl, preferably between 30 µl and 150 µl, more preferably between 40 µl and 60 µl. In one embodiment, the total volume of the reaction chamber can be 50 µl. The specification of the total volume can refer to the fluid volume encompassed by the one reaction chamber channel structure or the two or more reaction chamber channel structures as a whole.The reaction chamber can be configured such that a detection reagent can be introduced into it, preferably by drying it on the bottom surface. The detection reagent triggers, for example, a color reaction if the fluid contains a specific substance to be detected. In an exemplary embodiment, the intensity of the color change allows a conclusion to be drawn about the concentration of the substance to be detected in the fluid. In an alternative embodiment, two or more detection reagents can be introduced into the reaction chamber, for example, one after the other in the direction of flow. The reaction chamber unit explained above can be comprised of a microfluidic test carrier comprising a test carrier base element, wherein the reaction chamber unit can be arranged in the test carrier base element.VEL-20396-P-WO - 27 - Orphan Diagnostics AS The microfluidic test carrier described above can be designed as a single-use test carrier. This avoids contamination and eliminates the need for cleaning. The devices according to the invention are not limited to the applications and embodiments described above. In particular, to fulfill a functionality described herein, they can have a number of individual elements, components, units, and method steps that differs from the number stated herein. Furthermore, in the value ranges stated in this disclosure, values ​​lying within the stated limits are also to be considered disclosed and can be used as desired. The present invention is described below by way of example with reference to the attached figures. The drawings, the description, and the claims contain numerous features in combination.A person skilled in the art will expediently consider the features individually and use them sensibly in combination within the scope of the claims. If there is more than one example of a particular object, only one of them may be provided with a reference symbol in the figures and in the description. The description of this example can be transferred accordingly to the other examples of the object. If objects are named in particular using numerical words, such as first, second, third object, etc., these serve to name and / or assign objects. Accordingly, for example, a first object and a third object, but not a second object, may be included. However, a number and / or a sequence of objects could also be derived from numerical words. In the drawings: Fig. 1 shows a schematic representation of a microfluidic test carrier; Fig.2a-b show a schematic representation of a movement element of the microfluidic test carrier in a side view (Fig. 2a) and a top view (Fig. 2b); Fig. 3a-b show a schematic representation of the movement element in a first position (Fig. 3a) and in a second position (Fig. 3b); VEL-20396-P-WO - 28 - Orphan Diagnostics AS Fig. 4 shows a schematic representation of an embodiment of a fluid-bundling test carrier channel structure; Fig. 5 shows a schematic representation of an embodiment of a fluid-storing test carrier channel structure; Fig. 6 shows a schematic representation of an alternative embodiment of a fluid-storing test carrier channel structure; Fig. 7a shows a schematic representation of an embodiment of a reaction chamber structure; Fig. 7b-d show cross sections through the reaction chamber structure according to the section lines AA and BB in Figs. 7a and 7b, as well as an enlarged section of a structural section marked in Fig. 7c in Fig. 7d;Figure 8 shows a schematic representation of an alternative embodiment of the reaction chamber structure with two parallel reaction chamber channel structures; Figures 9a-c show schematic representations of alternative embodiments of the reaction chamber structure; and Figure 10 shows a schematic representation of the microfluidic test carrier with a user interface. Figure 1 shows a schematic representation of a microfluidic test carrier 10. The microfluidic test carrier 10 comprises a test carrier base element 12 in which a first microfluidic test carrier channel structure 14 and a second microfluidic test carrier channel structure 16 are arranged. In the illustrated embodiment, the first test carrier channel structure 14 comprises a sample receptacle 18, a fluid-bundling test carrier channel structure 20, and a vent channel 22.Furthermore, in the illustrated embodiment, the second test carrier channel structure 16 comprises a fluid-storing test carrier channel structure 24, a mixing structure 26, and a reaction chamber unit 28. In the present case, the microfluidic test carrier 10 further comprises a movement element 30 with a microfluidic movement element channel structure 32. The movement element channel structure 32 comprises an inlet opening 34 and an outlet opening 36. The movement element 30 is movable relative to the test carrier base element 12 between a first position shown in Fig. 3a and a second position shown in Fig. 3b. In the first position of the movement element 30, the inlet opening 34 of the movement element 30 is in fluid communication with the first test carrier channel structure 14.In the second position of the moving element 30, the fluid communication between the first test carrier channel structure 14 and the moving element channel structure 32 is interrupted. In the second position, the moving element channel structure 32 is in fluid communication with the second test carrier channel structure 16. In the illustrated embodiment, an operating element 38 that can be actuated by an operator is provided for moving the moving element 30. The operating element 38 is movably received in the test carrier base element 12, for example, by means of a pivotable bolt-and-pin connection 40. When actuated, the operating element 38 can act on the moving element 30 such that it moves from the first to the second position. For example, the operating element 38 has a projection 42 that acts on a front end of the moving element 30.To ensure good handling, the microfluidic test carrier 10 can have a gripping area 44. The gripping area 44 is free of functional structures, such as microfluidic channels, so that the operator can easily grasp and hold the microfluidic test carrier 10. The structure and functionality of the movement element 30 are described in more detail below with reference to Figures 2a-2b and 3a-3b. In general, the movement element 30 is designed to move a fluid volume. The fluid volume is received in the movement element channel structure 32 and, when the movement element 30 moves, is moved together with it. When the movement element 30 moves, there is no relative movement between the movement element 30 and the fluid received therein.If the movement element 30 is in the first position, a fluid sample applied to the sample holder 18 can flow into the movement element channel structure 32 via the inlet opening 34. With the movement of the movement element 30, the fluid volume held in the movement element channel structure 32 is transferred. In the second position, this fluid volume can flow into a section of the second test carrier channel structure 16. The fluid volume held in the movement element channel structure 32 can flow out of the movement element channel structure 32 via the outlet opening 36. A possible embodiment of the movement element channel structure 32 as a microfluidic channel with a rectangular cross-section can be seen in the side view of the movement element 30 in Fig. 2a. As can be seen in the top view of the movement element 30 in Fig.2b, a width 46 of the moving element 30 in the region of the moving element channel structure 32 is greater than a width 48 of the moving element 30 adjacent to the moving element channel structure 32. As can be seen in Figures 2a-2b, the moving element channel structure 32 projects beyond an adjoining moving element web 50 in two width directions and / or two depth directions. Figures 3a and 3b show the moving element 30 received in a receiving area 52 of the test carrier base element 12. A boundary surface 54 of the receiving area 52 contacts the inlet opening 34, and a boundary surface 56 of the receiving area 52 contacts the outlet opening 36 of the moving element channel structure 32. If the moving element 30 is inserted into the receiving area 52, as shown in Figures 3a-3b, a cavity 58 is located in the receiving area 52.The cavity 58 is delimited by the boundary surfaces 54, 56 of the receiving area 52 and by walls 60 of the moving element channel structure 32. More precisely, the cavity 58 is provided in the width direction between the moving element web 50 of the moving element 30 and the boundary surfaces 54, 56 of the receiving area 52. Alternatively or additionally, the cavity 58 is provided in the depth direction between the moving element web 50 and a cover surface of the receiving area 52. At least one microfluidic channel of the second test carrier channel structure 16 opens into the cavity 58 when the moving element 30 is in the first position. In this way, a fluid stop is achieved, i.e., fluid located in the second test carrier channel structure 16 does not flow into the cavity 58.Furthermore, at least one microfluidic channel of the first test carrier channel structure 14 opens into the receiving area 52 when the moving element is in the second position. The fluid stop is also achieved by a sharp-edged transition of the channels into the receiving area 52 or the cavity 58. Preferably, an angle between the boundary surfaces 54, 56 and the opening channels is an acute angle. VEL-20396-P-WO - 31 - Orphan Diagnostics AS Precise positioning of the moving element 30 in the first or second position is achieved by a first stop 62 and a second stop 64, which are each formed by the test carrier base element 12. The fluid volume movable by the moving element 30 is determined by the dimensioning of a channel length 66, a channel depth 68, and a channel width 70 of the moving element channel structure 32.In one embodiment, the above dimensions are selected such that the moving element channel structure 32 is configured to accommodate a fluid volume of 1 µl. The channel length 66 of the moving element channel structure 32 is, for example, between 0.5 mm and 10 mm, preferably between 2 mm and 8 mm, more preferably between 3 mm and 5 mm. The channel depth 68 and / or the channel width 70 of the moving element channel structure 32 is / are, for example, between 100 µm and 1000 µm, preferably between 300 µm and 800 µm, more preferably between 400 µm and 600 µm. The first test carrier channel structure 14 and / or the second test carrier channel structure 16 can have an identical channel depth 68 and / or channel width 70. In this way, fluid can easily flow into and / or out of the moving element channel structure 32. Fluid can flow into the moving element channel structure 32 by means of capillary force.For example, a gas volume in the moving element channel structure 32 can escape via the ventilation channel 22. The moving element channel structure 32 and / or the ventilation channel 22 can have sufficient capillary force to completely fill the moving element channel structure 32 with fluid. As can be seen in Fig. 3a, in the first position of the moving element 30, a gas volume is located in a gas-filled chamber 74 between the boundary surfaces 54, 56 of the receiving area 52 and an enlarged end area 76 of the moving element 30. If the moving element 30 is moved from the first to the second position, i.e., moved to the right in the drawing of Fig. 3a, the gas volume of the gas-filled chamber 74 can flow into a ventilation structure 72. The enlarged end area 76 of the moving element 30 prevents the gas volume from flowing into the cavity 58.As can be seen in Figure 1, the ventilation structure 72 is in fluid communication with the second test carrier channel structure 16 such that the gas can flow from the gas-filled chamber 74 via the ventilation structure 72 into the second test carrier channel structure 16. Alternatively or additionally, the gas can escape from the gas-filled chamber 74 into the environment via the ventilation structure 72. VEL-20396-P-WO - 32 - Orphan Diagnostics AS Possible embodiments of the first test carrier channel structure 14 are explained in more detail below. As explained at the beginning in the description of the figures, in the present embodiment, the first test carrier channel structure 14 comprises the sample receptacle 18, the fluid-bundling test carrier channel structure 20 and / or the ventilation channel 22. The sample receptacle 18 is arranged in the test carrier base element 12, for example in the form of a recessed receiving surface. A liquid fluid sample, for example, blood, urine, serum, saliva, etc., is placed by an operator onto the sample holder 18. The fluid-bundling test carrier channel structure 20 shown in Fig. 4 adjoins the sample holder 18 in the direction of flow. The fluid-bundling test carrier channel structure 20 comprises a receiving chamber 78 which is designed to receive a fluid. An absorbent fleece (not shown) is arranged, for example, in the receiving chamber 78 and sucks fluid from the sample holder into the receiving chamber 78. Alternatively or additionally, fluid can reach the receiving chamber 78 by means of capillary force or due to the creeping behavior of the fluid. Furthermore, the sample holder 18 and the receiving chamber 78 can be designed as a common functional area. In the embodiment shown, three sections 80, 82, 84 of the fluid-bundling test carrier channel structure 20 adjoin the receiving chamber 78. Four parallel fluid channels 86, 88, 90, 92 are arranged in the first section 80.All fluid channels 86, 88, 90, 92 of the first section 80 originate from the receiving chamber 78. Two fluid channels 86, 88 of the first section 80 meet to form another fluid channel 94 of the second section 82. The other two fluid channels 90, 92 of the first section 80 also meet to form another fluid channel 96 of the second section 82. The other fluid channels 94, 96 run parallel to one another. The cross-sectional area of ​​the other fluid channel 94 of the second section 82 is smaller than the cross-sectional areas of the two fluid channels 86 and 88 of the first section 80 combined. The cross-sectional area of ​​the other fluid channel 94 of the second section 82 is larger than each of the cross-sectional areas of the fluid channels 86, 88 of the first section. It is conceivable that two, three, four or more channels of a section, e.g. the first section 80, are connected to another channel of a section following in the direction of flow, e.g.of the second section 82. The further fluid channels 94, 96 of the second section 82 open into a fluid-bundling channel 98. Consequently, the fluid channels 86, 88, 90, 92 and the further fluid channels 94, 96 are in fluid communication with the fluid-bundling channel 98. The fluid-bundling channel 98 can be regarded as a third section 84 of the fluid-bundling test carrier channel structure 20. The fluid-bundling channel 98 has a cross-sectional area that is larger than the cross-sectional area of ​​each of the other fluid channels 90 and 94 of the second section 82. The fluid-bundling test carrier channel structure 20 enables fluid applied to the sample receptacle 18 to be transported by capillary force, specifically from the sample receptacle 18 via the fluid-bundling test carrier channel structure 20 to the moving element channel structure 32.Fluid absorbed by the moving element channel structure 32 flows further into the vent structure 22. Gas volume displaced by the absorbed fluid is released into the environment by means of the vent structure 22. The vent structure 22 comprises an opening 23 open to the environment, from which gas can escape. For reproducible fluid transport through the fluid-bundling test carrier channel structure 20, the following dimensions of the fluid channels 86-92 of the first section 80 may be particularly suitable. Each fluid channel of the fluid channels 86-92 of the first section 80 may have a cross-sectional area that is less than 0.2 mm² and greater than 0.1 mm², preferably less than 0.17 mm² and greater than 0.13 mm². In the illustrated embodiment, the cross-sectional area of ​​each of the fluid channels 86-92 is 0.15 mm².Each of the further fluid channels 94, 96 of the second section 82 can have a cross-sectional area that is less than 0.25 mm² and greater than 0.15 mm², preferably less than 0.23 mm² and greater than 0.18 mm². In the illustrated embodiment, the cross-sectional area of ​​each of the further fluid channels 94, 96 is 0.2 mm². The fluid concentrating channel 98 of the third section 84 can have a cross-sectional area that is less than 0.3 mm² and greater than 0.2 mm², preferably less than 0.28 mm² and greater than 0.23 mm². In the illustrated embodiment, the cross-sectional area of ​​the fluid concentrating channel is 0.25 mm². It is understood that the first section 80 comprises at least two fluid channels 86, 88, but may comprise any number of fluid channels. In the illustrated embodiment, the first section 80 comprises four parallel fluid channels 86, 88.For example, the first section may also comprise two, three, five, six, seven, eight, or more parallel fluid channels. The second section 82 comprises at least one further fluid channel 64. In the illustrated embodiment, the second section 82 comprises two parallel fluid channels 94, 96. For example, the second section 82 may also comprise four, five, six, or more parallel fluid channels. The number of further fluid channels in the second section 82 is fewer than the number of fluid channels in the first section 80. The third section 84 comprises at least one fluid channel, for example, the fluid-bundling channel 98. However, the third section 84 may also comprise two, three, or more fluid channels. The number of fluid channels in the third section 84 is fewer than the number of fluid channels in the second section 82.Furthermore, one or more further fluid channels can adjoin the third section 84, which open into a common fluid-bundling channel 98. Possible embodiments of the second test carrier channel structure 16 are explained in more detail below. As explained at the beginning in the description of the figures, the second test carrier channel structure 16 in the present embodiment comprises the fluid-storing test carrier channel structure 24, the mixing structure 26 and / or the reaction chamber unit 28. In the present embodiment, the second test carrier channel structure 16 comprises the fluid-storing test carrier channel structure 24. The fluid-storing test carrier channel structure 24 is configured to accommodate a fluid. The fluid can be accommodated in such a way that, during transport of the microfluidic test carrier 10, it can be transported together with the fluid-storing test carrier channel structure 24 without leaking.The microfluidic structures of the fluid-storing test carrier channel structure 24 are sealed, for example, by means of a cover film. Fig. 5 shows the fluid-storing test carrier channel structure 24 schematically in a top view, with the movement element 30 in the second position. In this second position, the fluid-storing test carrier channel structure 24 is in direct fluid communication with the movement element channel structure 32. The fluid stored in the fluid-storing test carrier channel structure 24 can flow into the movement element channel structure 32 and displace a fluid present in the movement element channel structure 32. Furthermore, the fluid present in the movement element channel structure 32 is diluted with the fluid of the fluid-storing test carrier channel structure 24.Furthermore, in the flow direction from the fluid-storing test carrier channel structure 24 to the moving element channel structure 32, the mixing structure 26 can be connected, which serves to ensure thorough mixing of the fluid in the fluid-storing test carrier channel structure 24 and the fluid in the moving element channel structure 32. VEL-20396-P-WO - 35 - Orphan Diagnostics AS In the fluid-storing test carrier channel structure 24, a large part of the absorbed fluid is present in a storage section 100. In the embodiment of the fluid-storing test carrier channel structure 24 shown in Fig. 5, the storage section 100 is designed in a meander shape. A channel width 101 of the meander can be between 2 mm and 0.8 mm, preferably between 1.8 mm and 1 mm, more preferably between 1.6 mm and 1.2 mm. A channel depth of the meander can be between 1.9 mm and 0.7 mm, preferably between 1.7 mm and 0.9 mm, more preferably between 1.5 mm and 1.1 mm. Fig.6 shows an alternative embodiment of the fluid-storing test carrier channel structure 24, in which the storage section 100 is designed as a continuous storage space 102. The storage section 100 can be configured to accommodate a fluid volume that is greater than 20 µl and less than 300 µl. For example, the storage section is configured to accommodate a fluid volume between 20 µl and 150 µl, preferably between 25 µl and 100 µl, more preferably between 40 µl and 120 µl. It is understood that the accommodated fluid volume can comprise a liquid or a mixture of a liquid and a gas. Adjoining the storage section 100 in the flow direction is a section with a channel cross-sectional constriction 104 and a fluid outlet 106. The fluid outlet 106 opens into the movement element channel structure 32.A channel cross-section of the fluid outlet 106 is many times smaller than a channel cross-section of the storage section 100, for example, at least half as large. In the section of the channel cross-section constriction 104, the channel cross-section is continuously reduced in the direction of flow. A capillary force in the section of the channel cross-section constriction 104 and / or in the fluid outlet 106 makes it possible to draw fluid out of the storage section 100. The dimensions of the storage section 100 are selected such that a capillary force of the feed section 100 is negligible compared to a capillary force in the section of the channel cross-section constriction 104 and / or in the region of the fluid outlet 106.To ensure that the fluid contained in the storage section 100 can flow out of the fluid-storing test carrier channel structure 24, a gas inlet 108 is provided, which is arranged at an end of the fluid-storing test carrier channel structure 24 opposite the fluid outlet 106. The gas inlet 108 can be in fluid communication with a flow connection 110 open to the environment, so that ambient air can flow into the gas inlet 108. The gas inlet 108 is also in fluid communication with the vent structure 72 and consequently in fluid communication with the gas-filled chamber 74. When the moving element 30 is moved from the first to the second position, the gas escapes from the gas-filled chamber 74 via the vent structure 72 and is forced into the gas inlet 108 of the fluid-storing test carrier channel structure 24.In this way, a partial volume of the fluid located in the storage section 100 is pressed out of the storage section 100 in the flow direction to the fluid outlet 106. This pressure due to the movement of the moving element 30 facilitates emptying of the storage section 100. The ventilation structure 72, the gas inlet 108, and the flow connection 110 converge in a gas distribution chamber 112. A cross-sectional area of ​​the gas distribution chamber 112 is at least 50%, preferably at least 100%, more preferably at least 150% larger than that of the gas inlet 108. In the present embodiment, the second test carrier channel structure 16 comprises the reaction chamber unit 28, which is shown in Fig. 7a. The reaction chamber unit 28 comprises a reaction chamber 114. A fluid inlet 116 is provided through which a fluid can flow into the reaction chamber unit 114.Furthermore, a gas outlet 118 is provided, through which a gas can escape from the reaction chamber 114 when fluid flows into the reaction chamber unit 114 through the fluid inlet 116. The reaction chamber unit 114 comprises a reaction chamber channel structure 120 in which a fluid can flow. Fig. 7a shows an exemplary embodiment of the reaction chamber channel structure 120 in a meander shape. The reaction chamber channel structure 120 is formed between the fluid inlet 116 and the gas outlet 118. In an alternative embodiment shown in Fig. 8, two reaction chamber channel structures 122, 124 are arranged between the fluid inlet 116 and the gas outlet 118. The reaction chamber channel structure 122 provides a fluidically connected channel structure, and the reaction chamber channel structure 124 provides another fluidically connected channel structure.At the fluid inlet 116, the fluid flowing into the reaction chamber 114 is divided, for example, equally into the two reaction chamber channel structures 122, 124 by means of a flow dividing structure 126. VEL-20396-P-WO - 37 - Orphan Diagnostics AS Further alternative embodiments of the reaction chamber 114 are conceivable. Fig. 9a, for example, shows a reaction chamber 114 with a circular shape. A fluid flowing in through the fluid inlet 116 flows along a central channel 128 through the reaction chamber 114. Starting from the central channel 128, several flow channels 130, 132, 134, 136, 138 branch off in a semicircular shape in the first half of the reaction chamber 114 and meet again at the central channel 128 in the second half of the reaction chamber 114. The central channel 128 opens into the gas outlet 118. Fig. 9b shows a further alternative embodiment of the reaction chamber 114 with a circular shape.Here, too, a central channel 128 runs from the fluid inlet 116 to the gas outlet 118. Furthermore, several flow channels 130, 132, 134, 136, 138 branch off from the central channel 128 in the first half of the reaction chamber 114. However, the flow channels 130, 132, 134, 136 end at least partially in the second half of the reaction chamber 114 without opening into the central channel 128. For example, one of the two stages of different depths of the reaction chamber 114 ends before it opens into the central channel 128. Yet another alternative embodiment of the reaction chamber 114 is shown in Fig. 9c, in which the reaction chamber channel structure 120 runs in a spiral shape. The fluid inlet 116 represents the beginning of the spiral, and the gas outlet 118 represents the end of the spiral.A cross-section through the alternative embodiments of the reaction chamber, as shown in Figures 9a, 9b, and 9c, comprises two reaction chamber depths, comparable to the illustrations in Figures 7b to 7d. The following is an explanation of the structure of the reaction chamber 114 using the example of the embodiment shown in Figure 7a and the two cross sections AA and B-B through the reaction chamber 114, which are shown in Figures 7b-7d. The reaction chamber 114 has a bottom surface 140 and a side surface 142 that adjoins the bottom surface 140. As can be seen in the cross-sectional views in Figures 7b-7d, the reaction chamber 114 has two different reaction chamber depths 144, 146. In other words, the reaction chamber comprises two stages of different depths. In the illustrated embodiment, a first reaction chamber depth 144 is greater than a second reaction chamber depth 146.VEL-20396-P-WO - 38 - Orphan Diagnostics AS The two different stages in the reaction chamber 114 are achieved by a microfluidic channel structure 148 extending from the bottom surface 140 into a flow space 150 of the reaction chamber 114. The flow space 150 is understood to be a space that extends from the bottom surface 140 to a cover surface 154 of the reaction chamber 114. In Fig. 7b, the flow space is shown by dotted lines. By means of the microfluidic channel structure 148, a reaction chamber channel 152 is formed, which is arranged in a region of the first reaction chamber depth 144. The depth of the reaction chamber channel 152 is less than the first reaction chamber depth 144. In other words, the reaction chamber channel 152 does not extend over the entire reaction chamber 114, but only in the region of the microfluidic channel structure.Adjacent to the reaction chamber channel 152 is a flow field 156, which is provided in the second reaction chamber depth 146. The flow field 156 is shown in dotted lines in Fig. 7b. The flow space 150 and the flow field 156 are in fluid communication with each other. If a fluid is present at the fluid inlet 116, this fluid is drawn into the reaction chamber 114 by a capillary force in the reaction chamber channel 152. Initially, the fluid moves along a first reaction chamber channel section 152a. The capillary force in the first reaction chamber channel section 152a is sufficiently large that the fluid above the first reaction chamber channel section 152a in the region of the second reaction chamber depth 146 moves in accordance with the movement of the fluid in the first reaction chamber channel section 152a.After the fluid has passed through the first reaction chamber channel section 152a, it will flow through a first meander loop 158 due to capillary force and reach a second reaction chamber channel section 152b. Even in the region of the meander loop 158, the capillary force in the reaction chamber channel 152 is sufficiently strong to also draw adjacent fluid in the region of the second reaction chamber depth 146 around the meander loop 158. The fluid then flows through the further reaction chamber channel sections and meander loops until the fluid has filled the last reaction chamber channel section 152c in the flow direction and ultimately reaches the gas outlet 118. The entire reaction chamber 114 is then filled with fluid. By way of example, a depth 160 of the flow field 156 is between 100 µm and 500 µm, preferably between 150 µm and 400 µm, more preferably between 200 µm and 300 µm.The flow field 156 can have a continuous area between 130 mm² and 70 mm², preferably between 120 mm² and 80 mm², more preferably between 110 mm² and 90 mm². For example, VEL-20396-P-WO - 39 - Orphan Diagnostics AS, a depth 162 of the reaction chamber channel 152 is between 300 µm and 700 µm, preferably between 400 µm and 600 µm, more preferably between 450 µm and 550 µm. A width 164 of the reaction chamber channel 152 is, for example, between 100 µm and 700 µm, preferably between 200 µm and 600 µm, more preferably between 300 µm and 550 µm. A detection reagent can be present in the region of the reaction chamber 114, preferably on the bottom surface 140. The detection reagent can, for example, adhere to the bottom surface 140. As soon as fluid comes into contact with the detection reagent, components of the fluid can react with the detection reagent and, for example, cause a color reaction.Due to the continuous flow field 156 across the entire reaction chamber 114, such a color reaction is evenly distributed throughout the reaction chamber 114 and can be easily detected using optical measurement methods. The reaction chamber 114, with its graduated structure, thus offers fast, reliable, and homogeneous filling of the reaction chamber as well as an optically analyzable measurement surface. It is understood that in the case of two separate reaction chamber channel structures 122, 124, as shown by way of example in Figure 8, a different detection reagent can be present in each reaction chamber channel structure 122, 124. This enables the analysis of a fluid for two different components using one microfluidic test carrier. Furthermore, the detection reactions run in parallel, thereby saving time.The reaction chamber 114 can accommodate a total volume of between 20 µl and 200 µl, preferably between 30 µl and 150 µl, more preferably between 40 µl and 60 µl. To achieve complete filling of the reaction chamber 114 with fluid, it is advantageous for the gas outlet 118 to be open throughout the entire filling process, allowing gas to flow out through it. Small amounts of fluid at the gas outlet 118 could easily clog it and lead to incomplete filling of the reaction chamber 114 with fluid. To prevent fluid from creeping along the side surface 142 and wetting the gas outlet 118 during the filling process, a projection 166 is provided. The projection 166 is arranged on at least one side surface section 168 and projects into the flow space 150. Figures 7a-7b show a possible arrangement of the projection 166 adjacent to the gas outlet 118 and adjacent to the last reaction chamber channel section 152c.A fluid creeping from the fluid inlet 116 along the side surface portion 168 toward the gas outlet 118 encounters the projection 166, which stops the fluid creeping process or at least prevents it from filling the reaction chamber 114 faster than the fluid can creep to the gas outlet 118. When the reaction chamber 114 is completely filled with fluid, the fluid is present at the gas outlet 118. It is desirable that the fluid cannot escape from the reaction chamber 114 via the gas outlet 118. For this reason, it is advantageous that the gas outlet has a cross-sectional area that is smaller than a cross-sectional area of ​​the reaction chamber channel 152. Preferably, the cross-sectional area of ​​the gas outlet is more than 50% smaller than the cross-sectional area of ​​the reaction chamber channel 152, preferably more than 75% smaller.The gas outlet has, for example, a cross-sectional area between 0.08 mm² and 0.02 mm², preferably between 0.06 mm² and 0.03 mm², more preferably 0.04 mm². The gas outlet 118 is connected to a venting chamber 170 via a venting channel such that gas can flow from the gas outlet 118 into the venting chamber 170. The venting chamber 170 has a venting chamber opening 172 that is open to the environment. The venting chamber opening 172 has, for example, a cross-sectional area of ​​0.16 mm². Should a small amount of fluid escape from the gas outlet 118 of the reaction chamber 114, it would be absorbed into the venting chamber 170 without escaping from the microfluidic test carrier 10. In this way, contamination is avoided.The fluid structures shown here, such as the first test carrier channel structures 14 and the second test carrier channel structures 16, can be realized by means of depressions in the test carrier base element 12 and closed by means of a cover film 174. The movement element channel structure 32 can be realized by means of a depression in the movement element and closed by means of a cover film. The test carrier base element 12 can be made, for example, from a plastic material such as PMMA (polymethyl methacrylate), COC (cycloolefin copolymer), COP (cycloolefin polymer), PC (polycarbonate), or a combination of one or more of the aforementioned plastic materials. Fig. 10 shows the microfluidic test carrier 10 with a user interface 176. The user interface 176 comprises a measurement window 178, which is arranged adjacent to the reaction chamber 114 and through which the reaction chamber 114 is at least partially visible.Adjacent to the measurement window 178 is a color scale VEL-20396-P-WO - 41 - Orphan Diagnostics AS 180, to which specific concentrations of a fluid component are assigned. Depending on the color change in the measurement window 178, the user can determine which concentration of the fluid component to be detected is contained in the fluid in the reaction chamber 114. Furthermore, the user interface 176 indicates the area for the sample intake 18 and / or an actuation area 182 for the control element 38 for moving the movement element 30. VEL-20396-P-WO - 42 - Orphan Diagnostics AS List of Reference Symbols 10 microfluidic test carrier 12 test carrier base element 14 first microfluidic test carrier channel structure 16 second. 18 Sample intake 20 Fluid-bundling test carrier channel structure 22 Ventilation channel 24 Fluid-storing test carrier channel structure 26 Mixing structure 28 Reaction chamber unit 30 Movement element 34 Inlet opening of the moving element channel structure Connection 42 Projection of the operating element 44 Grip area 46 Width of the moving element in the area of ​​the moving element channel structure 48 Width of the moving element adjacent to the moving element channel structure VEL-20396-P-WO - 43 - Orphan Diagnostics AS 78 Recording chamber 80 first section of the fluid-bundling test carrier 82 second section of the fluid bundling 84 third section of the fluid-bundling test carrier channel structure 86-92 fluid channel of the first section 94-96 further fluid channel of the second section 98 fluid-bundling channel / fluid channel of the third section 100 storage section 101 channel width of the meander 102 104 Channel cross-section constriction 106 Fluid outlet of the fluid-storing test carrier 108 Gas inlet of the fluid-storing test carrier 110 Flow connection 112 Gas distribution chamber 114 Reaction chamber unit 116 Fluid inlet 118 120-124 126 Flow division structure 128 Central channel 130 - 138 Flow channel 140 Bottom surface 142 Side surface 144 First reaction chamber depth 146 Second reaction chamber depth 148 Microfluidic channel structure 150 Flow space 152 Reaction chamber channel 152a-c Reaction chamber channel section 154 Lid surface 156 Flow field 158 Meander loop 160 Depth of flow field 162 Depth of reaction chamber channel 164 Width of reaction chamber channel 166 Overhang 168 Side surface section 170 Vent chamber VEL-20396-P-WO - 44 - Orphan Diagnostics AS 172 Vent chamber opening 174 Lid foil 176 User interface 178 Measurement window 180 Color scale 182 Actuation area VEL-20396-P-WO - 45 - Orphan Diagnostics AS The disclosure relates, inter alia, to the following aspects: Aspect 1. A microfluidic test carrier (10) comprising: - a test carrier base element (12),- a first microfluidic test carrier channel structure (14) arranged in the test carrier base element (12), and - a movement element (30), comprising: - at least one microfluidic movement element channel structure (32), wherein the movement element channel structure (32) comprises an inlet opening (34) and an outlet opening (36), - wherein the movement element (30) is movable relative to the test carrier base element (12) between a first position and a second position, - wherein in the first position of the movement element (30), the inlet opening (34) of the movement element channel structure (32) is in fluid communication with the first test carrier channel structure (14), - wherein in the second position of the movement element (30), fluid communication between the movement element channel structure (32) and the first test carrier channel structure (14) is interrupted. Aspect 2. Microfluidic test carrier (10) according to aspect 1, further comprising a second test carrier channel structure (16),wherein, in the second position of the movement element (30), the movement element channel structure (32) is in fluid communication with the second test carrier channel structure (16). Aspect 3. Microfluidic test carrier (10) according to aspect 1 or 2, wherein the movement element channel structure (32) is configured to receive a quantity of fluid in the first position and to dispense this quantity of fluid in the second position. Aspect 4. Microfluidic test carrier (10) according to one of the preceding aspects, wherein a width (46) of the movement element (30) in the region of the movement element channel structure (32) is greater than a width (46) of the movement element (30) adjacent to the movement element channel structure (32). Aspect 5. Microfluidic test carrier (10) according to one of the preceding aspects, wherein the movement element (30) is received or can be received in a receiving area (52) VEL-20396-P-WO - 46 - Orphan Diagnostics AS of the test carrier base element (12) in such a way,that the inlet opening (34) of the movement element channel structure (32) and the outlet opening (36) of the movement element channel structure (32) directly contact a respective boundary surface (54, 56) of the receiving area (52). Aspect 6. The microfluidic test carrier (10) according to aspect 5, wherein a cavity (58) is provided between the movement element (30) and at least one of the boundary surfaces (54, 56) of the receiving area (52), which cavity adjoins the movement element channel structure (32) when the movement element (30) is inserted into the test carrier base element (12). Preferably, the cavity (58) adjoining the movement element channel structure (32) is provided between the movement element (30) and all adjacent boundary surfaces (54, 56) of the receiving area (52). Aspect 7. Microfluidic test carrier (10) according to aspect 6, wherein, when the moving element (30) is in the first position,the second test carrier channel structure (16) opens into the cavity (58). Aspect 8. The microfluidic test carrier (10) according to one of aspects 5 to 7, wherein the receiving region (52) forms two stops (62, 64) which limit the movement of the movement element (30) such that the movement element (30) is in the first position when it strikes the first stop (62) and is in the second position when it strikes the second stop (64). Aspect 9. The microfluidic test carrier (10) according to one of the preceding aspects, further comprising an operating element (38) which is connected to the movement element (30) such that it is configured to move the operating element (38) between the first and the second position, wherein the operating element (38) preferably projects beyond the test carrier base element (12) or is exposed such that an operator can actuate it. Aspect 10. Microfluidic test carrier (10) according to aspect 9,wherein the operating element (38) protrudes from the test carrier base element (12) and has an operating element projection that is connected or connectable to a locking element that prevents movement of the movement element VEL-20396-P-WO - 47 - Orphan Diagnostics AS (30) from the first to the second or from the second to the first position. Aspect 11. The microfluidic test carrier (10) according to one of the preceding aspects, wherein the movement element channel structure (32) has a channel length (66) that is between 0.5 mm and 10 mm, preferably between 2 mm and 8 mm, more preferably between 3 mm and 5 mm. Aspect 12. Microfluidic test carrier (10) according to one of the preceding aspects, wherein the moving element channel structure (32), the first test carrier channel structure (14) and / or the second test carrier channel structure (16) have a channel depth (68) and / or channel width (70) which is between 100 µm and 1000 µm, preferably between 300 µm and 800 µm,more preferably between 400 µm and 600 µm. Aspect 13. The microfluidic test carrier (10) according to any one of the preceding aspects, wherein a surface delimiting the movement element channel structure (32) is arranged at an acute angle or right angle to at least one of the outer surfaces of the movement element (30). Aspect 14. The microfluidic test carrier (10) according to any one of aspects 5 to 13, further comprising a ventilation structure (72) arranged in the test carrier base element (12), which is in fluid communication with the movement element (30) and / or the second test carrier channel structure (16). Aspect 15. The microfluidic test carrier (10) according to aspect 14, wherein the venting structure (72) is arranged in the test carrier base element (12) such that a gas volume displaced by moving the movement element (30) from the first to the second position flows into the venting structure (72). Aspect 16. The microfluidic test carrier (10) according to aspect 14,wherein the ventilation structure (72) is arranged in the movement element (30) such that fluid communication exists between the second test carrier channel structure (16) and the ventilation structure (72) when the movement element (30) is in the second position, and / or wherein fluid communication between the ventilation structure (72) and the second test carrier channel structure (16) is interrupted when the movement element (30) is in the first position. Aspect 17. Microfluidic test carrier (10) according to one of the preceding aspects, wherein fluid movement into and out of the movement element channel structure (32) is based, preferably exclusively, on fluid transport by means of capillary force and / or by means of suction force and / or by means of air pressure. Aspect 18. Microfluidic test carrier (10) according to one of aspects 2 to 17,wherein - the second test carrier channel structure (16) comprises a fluid-storing test carrier channel structure (24), in particular a fluid-storing test carrier channel structure (24) according to one of aspects 26 to 32, and - when the movement element (30) is in the second position, the fluid-storing test carrier channel structure (24) is in fluid communication with the movement element channel structure (32) such that a fluid stored in the fluid-storing test carrier channel structure (24) can flow into the movement element channel structure (32) and can displace and dilute a fluid located in the movement element channel structure (32). Aspect 19. The microfluidic test carrier (10) according to aspect 17, wherein the second test carrier channel structure (16) further comprises a mixing structure (26) that is in fluid communication with the movement element channel structure (32).when the movement element (30) is in the second position. Aspect 20. The microfluidic test carrier (10) according to aspect 17 or 18, wherein - the fluid-storing test carrier channel structure (24) comprises a fluid outlet (106) and is in fluid communication with a gas inlet (108) arranged at an end of the fluid-storing test carrier channel structure (24) opposite the fluid outlet (106), and - a gas-filled chamber (74), which has at least one boundary surface (75) formed by the movement element (30), is in fluid communication with the gas inlet (108). Aspect 21. Microfluidic test carrier (10) according to one of the preceding aspects, wherein VEL-20396-P-WO - 49 - Orphan Diagnostics AS - the first test carrier channel structure (14) comprises a fluid-bundling test carrier channel structure (20), in particular a fluid-bundling test carrier channel structure (20) according to one of aspects 36 to 43, for bundling fluid in a fluid-bundling channel (98),and - wherein the fluid-bundling test carrier channel structure (20) comprises: - the fluid-bundling channel (98), - a receiving chamber (78) configured to receive a fluid; - a first section (80) with at least two parallel fluid channels (86-92) originating from the receiving chamber (78), and - a second section (82) in which the at least two parallel fluid channels (86-92) of the first section (80) meet and form a further fluid channel (94, 96) whose cross-sectional area is smaller than that of the two parallel fluid channels (86-92) of the first section (80) combined. Aspect 22. The microfluidic test carrier (10) according to aspect 21, wherein, when the movement element (30) is in the first position, the fluid-bundling test carrier channel structure (20) is in fluid communication with the movement element channel structure (32) such thatthat a fluid present in the fluid-bundling test carrier channel structure (20) can flow into the moving element channel structure (32). Aspect 23. Microfluidic test carrier (10) according to one of aspects 2 to 20, wherein - the second test carrier channel structure (16) comprises a reaction chamber unit (28), in particular a reaction chamber unit (28) according to one of aspects 44 to 63, and - the reaction chamber unit (28) comprises: - a reaction chamber (114) comprising at least one reaction chamber channel structure (120), - a fluid inlet (116) through which a fluid can flow into the reaction chamber (114), and - a gas outlet (118) through which a gas can escape from the reaction chamber (114), - wherein the reaction chamber (114) is delimited by a bottom surface (140) and a side surface (142) adjoining the bottom surface (140), VEL-20396-P-WO - 50 - Orphan Diagnostics AS characterized in thatthat the reaction chamber (114) comprises at least a first reaction chamber depth (144) and a second reaction chamber depth (146) different from the first reaction chamber depth (144). Aspect 24. The microfluidic test carrier (10) according to aspect 23, wherein, when the movement element (30) is in the second position, the reaction chamber unit (28) is in fluid communication with the movement element channel structure (32) such that a fluid located in the movement element channel structure (32) can flow into the reaction chamber unit (28). Aspect 25. The microfluidic test carrier (10) according to any one of aspects 1 to 24,wherein the second microfluidic test carrier channel structure (16) comprises a fluid-storing test carrier channel structure (24) according to any one of aspects 26 to 32; or / and wherein the first microfluidic test carrier channel structure (14) comprises a fluid-bundling test carrier channel structure (20) according to any one of aspects 36 to 42; or / and wherein the second microfluidic test carrier channel structure (16) comprises a reaction chamber unit (28) according to any one of aspects 44 to 63. Aspect 26. A fluid-storing test carrier channel structure (24) for a microfluidic test carrier (10), in particular for a microfluidic test carrier (10) according to one of aspects 1 to 24, comprising: - a storage section (100) for storing fluid, - a fluid outlet (106) in fluid communication with the storage section (100), and - a gas inlet (108) in fluid communication with the storage section (100),which is arranged at an end of the fluid-storing test carrier channel structure (24) opposite the fluid outlet (106). Aspect 27. The fluid-storing test carrier channel structure (24) according to aspect 26, further comprising a section with a channel cross-sectional constriction (104) arranged adjacent to the fluid outlet (106) of the fluid-storing test carrier channel structure (24). VEL-20396-P-WO - 51 - Orphan Diagnostics AS Aspect 28. A fluid-storing test carrier channel structure (24) according to aspect 26 or 27, wherein the storage section (100), preferably the storage section (100) and the section with a channel cross-sectional constriction (104) together, is configured to accommodate a fluid volume between 20 µl and 150 µl, preferably between 25 µl and 100 µl, more preferably between 40 µl and 120 µl. Aspect 29. A fluid-storing test carrier channel structure (24) according to aspect 27 or 28,wherein a capillary force of the storage section (100) is negligible compared to a capillary force in the section of the channel cross-sectional constriction (104) and / or in the region of the fluid outlet (106). Aspect 30. Fluid-storing test carrier channel structure (24) according to one of aspects 26 to 29, wherein the storage section (100) has a meandering shape and the channel structure in the meandering shape has a channel width (101) between 2 mm and 0.8 mm, preferably between 1.8 mm and 1 mm, more preferably between 1.6 mm and 1.2 mm, and / or has a channel depth between 1.9 mm and 0.7 mm, preferably between 1.7 mm and 0.9 mm, more preferably between 1.5 mm and 1.1 mm. Aspect 31. Fluid-storing test carrier channel structure (24) according to any one of aspects 26 to 29, wherein the storage section (100) comprises a continuous storage space (102), wherein the continuous storage space (102) has a storage space width between 9 mm and 28 mm,preferably between 12 mm and 24 mm, more preferably between 15 mm and 20 mm, and / or wherein the continuous storage space (102) has a storage space length between 3 mm and 22 mm, preferably between 6 mm and 19 mm, more preferably between 10 mm and 16 mm. Aspect 32. Fluid-storing test carrier channel structure (24) according to aspect 31, wherein a storage space depth of the continuous storage space (102) is between 0.8 mm and 1.2 mm, preferably between 0.9 mm and 1.1 mm, more preferably 1 mm. VEL-20396-P-WO - 52 - Orphan Diagnostics AS Aspect 33. Fluid-storing test carrier channel structure (24) according to any one of aspects 26 to 32, wherein at least part of a surface of the storage section (100) is coated with a diffusion-barrier layer. Aspect 34. Microfluidic test carrier (10), in particular according to one of aspects 1 to 24, comprising: - a test carrier base element (12),- a fluid-storing test carrier channel structure (24) according to one of the preceding aspects 26 to 33 arranged in the test carrier base element (12), and - a movement element (30) arranged in the test carrier base element (12), which is movable into a first position and a second position, wherein a gas-filled chamber (74), which has at least one boundary surface (75) formed by the movement element (30), is in fluid communication with the gas inlet (108). Aspect 35. The microfluidic test carrier (10) according to aspect 34, wherein the movement element (30) and the gas inlet (108) are arranged such that a gas volume of the gas-filled chamber (74) is pressed into the gas inlet (108) when the movement element (30) is moved from the first to the second position. Aspect 36. Microfluidic test carrier (10) according to aspect 34 or 35, wherein the gas inlet (108) is preceded by a gas distribution chamber (112), the cross-sectional area of ​​which is at least 50%preferably at least 100%, more preferably at least 150% larger than that of the gas inlet (108). Aspect 37. Fluid-bundling test carrier channel structure (20) for a microfluidic test carrier (10), in particular for a microfluidic test carrier (10) according to any one of aspects 1-24, which is configured to bundle fluid in a fluid-bundling channel (98), comprising: - the fluid-bundling channel (98), - a receiving chamber (78) configured to receive a fluid; VEL-20396-P-WO - 53 - Orphan Diagnostics AS - a first section (80) with at least two parallel fluid channels (86-92) originating from the receiving chamber (78), and - a second section (82) in which the at least two parallel fluid channels (86-92) of the first section (80) meet and form a further fluid channel (94, 96),whose cross-sectional area is smaller than that of the two parallel fluid channels (86-92) of the first section (80) combined, - wherein the fluid-bundling channel (98) is in fluid communication with the fluid channels (86-92) of the first section (80) and the second section (82). Aspect 38. Fluid-bundling test carrier channel structure (20) according to aspect 37, wherein the first section (80) comprises four parallel-connected fluid channels (86-92) which originate from the common receiving chamber (78), wherein two of the parallel-connected fluid channels (86-92) each open into a respective further fluid channel (94, 96) of the second section (82), wherein each further fluid channel (94, 96) of the second section (82) has a cross-sectional area which is smaller than a cross-sectional area of ​​two parallel fluid channels (86-92) of the first section (80) combined. Aspect 39. Fluid-bundling test carrier channel structure (20) according to aspect 37 or 38,wherein the fluid-bundling test carrier channel structure (20) further comprises a third section (84) with the fluid-bundling channel (98), into which the further fluid channel(s) (94, 96) of the second section (82) open and whose cross-sectional area is larger than that of the further fluid channel (94, 96) of the second section (82). Aspect 40. The fluid-bundling test carrier channel structure (20) according to any one of aspects 37 to 39, further comprising an absorbent nonwoven that enables fluid transport through a structure of the absorbent nonwoven, wherein the receiving chamber (78) is configured to receive the absorbent nonwoven. Aspect 41. Fluid-bundling test carrier channel structure (20) according to any one of aspects 37 to 40, wherein each fluid channel of the fluid channels (86-92) of the first section (80) has a cross-sectional area that is less than 0.2 mm² and greater than 0.1 mm², preferably less than 0.17 mm² and greater than 0.13 mm², more preferably 0.15 mm²,and / or VEL-20396-P-WO - 54 - Orphan Diagnostics AS wherein the at least one further fluid channel (94, 96) of the second section (82) has a cross-sectional area that is less than 0.25 mm² and greater than 0.15 mm², preferably less than 0.23 mm² and greater than 0.18 mm², more preferably 0.2 mm². Aspect 42. Fluid-bundling test carrier channel structure (20) according to one of aspects 39 to 41, wherein the fluid-bundling channel (98) of the third section (84) has a cross-sectional area that is less than 0.3 mm² and greater than 0.2 mm², preferably less than 0.28 mm² and greater than 0.23 mm², more preferably 0.25 mm². Aspect 43. Fluid-bundling test carrier channel structure (20) according to any one of aspects 40 to 42, further comprising a sample receptacle (18), wherein the sample receptacle (18) and the receiving chamber (78) are in fluid communication such thatthat fluid applied to the sample holder (18) is drawn into the absorbent fleece arranged in the receiving chamber (78). Aspect 44. A microfluidic test carrier (10), in particular according to one of aspects 1 to 24, comprising: - a test carrier base element (12) and - a fluid-bundling test carrier channel structure (20) arranged in the test carrier base element (10) according to one of the preceding aspects 37 to 43. Aspect 45. A reaction chamber unit (28) for a microfluidic test carrier (10), in particular for a microfluidic test carrier (10) according to one of aspects 1 to 24, comprising: - a reaction chamber (114) comprising at least one reaction chamber channel structure (120), - a fluid inlet (116) through which a fluid can flow into the reaction chamber (114), and - a gas outlet (118) through which a gas can escape from the reaction chamber (114),- wherein the reaction chamber (114) is delimited by a bottom surface (140) and a side surface (142) adjoining the bottom surface (140), characterized in that VEL-20396-P-WO - 55 - Orphan Diagnostics AS the reaction chamber (114) comprises at least a first reaction chamber depth (144) and a second reaction chamber depth (146) different from the first reaction chamber depth (144). Aspect 46. The reaction chamber unit (28) according to aspect 45, wherein a microfluidic channel structure (148) extends from the bottom surface (140) of the reaction chamber (114) and projects into a flow space (150) of the reaction chamber (114). Aspect 47. Reaction chamber unit (28) according to aspect 46, wherein the microfluidic channel structure (148) comprises a reaction chamber channel (152) arranged in a region of the first reaction chamber depth (144),and whose channel depth (162) is less than the first reaction chamber depth (144). Aspect 48. Reaction chamber unit (28) according to aspect 47, wherein in a partial region of the first reaction chamber depth (144) and in the second reaction chamber depth (146) a flow field (156) is provided, which is in fluid communication with the microfluidic reaction chamber channel (152). Aspect 49. Reaction chamber unit (28) according to aspect 48, wherein the reaction chamber channel (152) has a capillary force that is greater than the capillary force of the flow field (156). Aspect 50. Reaction chamber unit (28) according to aspect 48 or 49, wherein the reaction chamber channel (152) is only partially enclosed by a wall, so that the reaction chamber channel (152) and the flow field (156) directly adjoin one another. Aspect 51. Reaction chamber unit (28) according to any one of aspects 48 to 50, wherein a depth (160) of the flow field (156) is between 100 µm and 500 µm,preferably between 150 µm and 400 µm, more preferably between 200 µm and 300 µm. Aspect 52. Reaction chamber unit (28) according to one of aspects 48 to 51, wherein the flow field (156) has a continuous area between 130 mm² and 70 mm², preferably between 120 mm² and 80 mm², more preferably between 110 mm² and 90 mm². VEL-20396-P-WO - 56 - Orphan Diagnostics AS Aspect 53. Reaction chamber unit (28) according to one of aspects 47 to 52, wherein a depth (162) of the reaction chamber channel (152) is between 300 µm and 700 µm, preferably between 400 µm and 600 µm, more preferably between 450 µm and 550 µm, or / and wherein a width (164) of the reaction chamber channel (152) is between 100 µm and 700 µm, preferably between 200 µm and 600 µm, more preferably between 300 µm and 550 µm. Aspect 54. Reaction chamber unit (28) according to any one of aspects 46 to 53, wherein a first side surface portion (168) of the at least one side surface,which connects the fluid inlet (116) and the gas outlet (118), has a projection (166) that projects into the flow space (150) and / or delimits the latter. Aspect 55. Reaction chamber unit (28) according to one of aspects 47 to 54, wherein the reaction chamber channel (152) runs meandering, spiraling, circularly and / or semicircularly within the flow space (150). Aspect 56. Reaction chamber unit (28) according to one of aspects 47 to 55, wherein the gas outlet (118) has a cross-sectional area that is smaller than a cross-sectional area of ​​the reaction chamber channel (152), preferably more than 50% smaller, more preferably more than 75% smaller. Aspect 57. Reaction chamber unit (28) according to any one of aspects 45 to 56, wherein the gas outlet (118) is connected to a venting chamber (170) via a venting channel such that gas can flow from the gas outlet (118) into the venting chamber (170). Aspect 58. Reaction chamber unit (28) according to aspect 57,wherein a volume of the venting chamber (170) is larger than a volume of the gas outlet (118), preferably more than 50% larger, preferably more than 100% larger, more preferably more than 200% larger. Aspect 59. The reaction chamber unit (28) according to aspect 57 or 58, wherein the venting chamber (170) is in fluid communication with a venting chamber opening (172), wherein the venting chamber opening (172) is configured such that gas can escape from the venting chamber (170) via it. VEL-20396-P-WO - 57 - Orphan Diagnostics AS Aspect 60. Reaction chamber unit (28) according to any one of aspects 45 to 59, wherein a microfluidic mixing structure (26) is arranged upstream of the fluid inlet (116) in the flow direction, wherein the mixing structure (26) comprises a microfluidic channel having at least one bend in its longitudinal extension. Aspect 61. Reaction chamber unit (28) according to any one of aspects 45 to 60,wherein exactly one fluidically connected reaction chamber channel structure (120) is arranged between the fluid inlet (116) and the gas outlet (118) of the reaction chamber (114). Aspect 62. Reaction chamber unit (28) according to one of aspects 45 to 60, wherein two or more reaction chamber channel structures (122, 124) are arranged between the fluid inlet (116) and the gas outlet (118) of the reaction chamber (114), each having a fluidically connected channel structure. Aspect 63. Reaction chamber unit (28) according to one of aspects 45 to 62, wherein a total volume of the reaction chamber (114) is between 20 µl and 200 µl, preferably between 30 µl and 150 µl, more preferably between 40 µl and 60 µl. Aspect 64. Reaction chamber unit (28) according to any one of aspects 45 to 63, wherein the reaction chamber (114) is configured such that a detection reagent can be introduced therein,preferably on the bottom surface (140) can be dried. Aspect 65. A microfluidic test carrier (10), in particular according to one of aspects 1-24, comprising: - a test carrier base element (12), - a reaction chamber unit (28) arranged in the test carrier base element (12) according to one of aspects 45 to 64. VEL-20396-P-WO,

Claims

- 58 - Orphan Diagnostics AS Patent Claims 1. A reaction chamber unit (28) for a microfluidic test carrier (10), comprising: - a reaction chamber (114) comprising at least one reaction chamber channel structure (120), - a fluid inlet (116) through which a fluid can flow into the reaction chamber (114), and - a gas outlet (118) through which a gas can escape from the reaction chamber (114), - wherein the reaction chamber (114) is delimited by a bottom surface (140) and a side surface (142) adjoining the bottom surface (140), - the reaction chamber (114) comprises at least a first reaction chamber depth (144) and a second reaction chamber depth (146) different from the first reaction chamber depth (144), - a microfluidic channel structure (148) extends from the bottom surface (140) of the reaction chamber (114), and protrudes into a flow space (150) of the reaction chamber (114),- the microfluidic channel structure (148) comprises a reaction chamber channel (152) arranged in a region of the first reaction chamber depth (144), the channel depth (162) of which is less than the first reaction chamber depth (144); - a flow field (156) is provided in a partial region of the first reaction chamber depth (144) and in the second reaction chamber depth (146), which flow field is in fluid communication with the microfluidic reaction chamber channel (152); and - the reaction chamber channel (152) has a capillary force that is greater than the capillary force of the flow field (156).

2. The reaction chamber unit (28) according to claim 1, wherein the reaction chamber channel (152) is only partially enclosed by a wall, so that the reaction chamber channel (152) and the flow field (156) directly adjoin one another.

3. Reaction chamber unit (28) according to claim 1 or 2, wherein a depth (160) of the flow field (156) is between 100 µm and 500 µm,preferably VEL-20396-P-WO, - 59 - Orphan Diagnostics AS is between 150 µm and 400 µm, more preferably between 200 µm and 300 µm.

4. Reaction chamber unit (28) according to one of the preceding claims, wherein the flow field (156) has a continuous area between 130 mm² and 70 mm², preferably between 120 mm² and 80 mm², more preferably between 110 mm² and 90 mm².

5. Reaction chamber unit (28) according to one of the preceding claims, wherein a depth (162) of the reaction chamber channel (152) is between 300 µm and 700 µm, preferably between 400 µm and 600 µm, more preferably between 450 µm and 550 µm, and / or wherein a width (164) of the reaction chamber channel (152) is between 100 µm and 700 µm, preferably between 200 µm and 600 µm, more preferably between 300 µm and 550 µm.Reaction chamber unit (28) according to one of the preceding claims, wherein a first side surface section (168) of the at least one side surface, which connects the fluid inlet (116) and the gas outlet (118), has a projection (166) that projects into and / or delimits the flow space (150).

7. Reaction chamber unit (28) according to one of the preceding claims, wherein the reaction chamber channel (152) runs meander-shaped, spiral-shaped, circular, and / or semicircular within the flow space (150).

8. Reaction chamber unit (28) according to one of the preceding claims, wherein the gas outlet (118) has a cross-sectional area that is smaller than a cross-sectional area of ​​the reaction chamber channel (152), preferably more than 50% smaller, more preferably more than 75% smaller. 9.Reaction chamber unit (28) according to one of the preceding claims, wherein the gas outlet (118) is connected to a venting chamber (170) via a venting channel such that gas can flow from the gas outlet (118) into the venting chamber (170).

10. Reaction chamber unit (28) according to claim 9, wherein a volume of the venting chamber (170) is greater than a volume of the gas outlet (118), VEL-20396-P-WO. - 60 - Orphan Diagnostics AS is preferably more than 50% larger, preferably more than 100% larger, more preferably more than 200% larger.

11. The reaction chamber unit (28) according to claim 9 or 10, wherein the venting chamber (170) is in fluid communication with a venting chamber opening (172), wherein the venting chamber opening (172) is configured such that gas can escape from the venting chamber (170) via it.

12. The reaction chamber unit (28) according to any one of the preceding claims, wherein a microfluidic mixing structure (26) is arranged upstream of the fluid inlet (116) in the flow direction, wherein the mixing structure (26) comprises a microfluidic channel having at least one bend in its longitudinal extension.Reaction chamber unit (28) according to one of the preceding claims, wherein exactly one fluidically connected reaction chamber channel structure (120) is arranged between the fluid inlet (116) and the gas outlet (118) of the reaction chamber (114).

14. Reaction chamber unit (28) according to one of claims 1 to 12, wherein two or more reaction chamber channel structures (122, 124) are arranged between the fluid inlet (116) and the gas outlet (118) of the reaction chamber (114), each having a fluidically connected channel structure.

15. Reaction chamber unit (28) according to one of the preceding claims, wherein a total volume of the reaction chamber (114) is between 20 µl and 200 µl, preferably between 30 µl and 150 µl, more preferably between 40 µl and 60 µl. 16.Reaction chamber unit (28) according to one of the preceding claims, wherein the reaction chamber (114) is configured such that a detection reagent can be introduced into it, preferably dried onto the bottom surface (140).

17. A microfluidic test carrier (10), comprising: - a test carrier base element (12), VEL-20396-P-WO. - 61 - Orphan Diagnostics AS - a reaction chamber unit (28) according to one of the preceding claims arranged in the test carrier base element (12). VEL-20396-P-WO

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