Container for small liquid volumes

Abstract

The invention relates to a container (1) for small liquid volumes, having at least one inlet chamber (2), at least one outlet chamber (3), an open top end (4) and a bottom end (5), wherein the bottom end (5) comprises at least one access region (7); wherein the at least one inlet chamber (2) is capable of accommodating a swab stick (16); wherein the at least one inlet chamber (2) has at least one open top end (11a) and is connectable to at least a first free end (8) of a flow path (9) via the at least one access region (7); and wherein the at least one outlet chamber (3) has at least one open top end (11b) and is connectable to at least a further free end (10) of the flow path (9) via the at least one access region (7); to a kit, to an interface for fluid transport and to a method for analyzing a sample liquid (18).

Description

[0001] This invention relates to a container, kit, and interface for fluid transport, a method for analyzing sample liquids, and the use of said container.

[0002] The delivery of liquid samples (e.g., liquids containing biological material) inherently requires sample dishes or containers in which the sample is held until further use. In order to perform any type of work or analysis on the held liquid sample, it is often unavoidable to transfer the liquid sample from one container to another or to another device, such as to different reaction tubes, to mixing devices, or to an analytical instrument that includes an analytical unit.

[0003] However, whenever work is performed on liquid samples, several risks arise, such as the risk of losing at least a portion of the sample volume (e.g., due to spillage), leading to poor reproducibility of the analysis performed on the liquid sample. Furthermore, the step of transferring or transporting liquid samples is typically associated with a significant loss of processing speed, and therefore with a loss of processing efficiency. Another risk associated with liquid transfer is the risk of liquid leakage into the instrument, resulting in, for example, damage to the instrument's electronics.

[0004] Especially when dealing with irritating or unstable chemicals, biomolecules (such as nucleic acids or proteins), or microorganisms, it is crucial to transfer liquid samples quickly, safely, and without spillage from one container to another or to an analytical instrument.

[0005] More challenging is that once the sample liquid has been successfully transferred from the first container to the second container, such as an analytical instrument, and once the sample liquid has been further processed in the second container, such as being analyzed, it becomes necessary to remove the sample from the analytical instrument so that the analytical instrument and the flow path leading there remain clean and become available for analyzing the next sample.

[0006] In the field of hygiene monitoring, surface microbial contamination testing is performed. This typically involves wiping the surface with a swab strip to collect a sample, which is then transferred to a liquid and analyzed to determine the presence of microorganisms. Essentially, this field requires the delivery of relatively small amounts of liquid, making spill-free and leak-free delivery particularly important.

[0007] One method for analyzing microorganisms collected from surfaces is to determine colony-forming units (CFUs), which are the number of cells capable of proliferating and forming cell colonies. This method relies on the prerequisite that the collected cells are indeed capable of growing on the provided growth medium. Another drawback of CFU determination is the time required for microorganisms to form colonies visible to the experimenter. Depending on the microbial species, the expected timeframe for obtaining results is several days rather than hours.

[0008] Alternatively, many current assay systems rely on indirectly determining the biomaterial by screening for the availability of the molecule adenosine triphosphate (ATP). This molecule is produced by cells to provide energy for many biological processes. Therefore, ATP is a reliable indicator of the at least temporary presence of living cells at a specific location. Due to the indirect nature of the method, it is impossible to distinguish between dead and living cells, as the detected ATP could originate from either. Furthermore, because ATP is widely present in almost all living cell taxa, it is impossible to distinguish whether the identified ATP originated from, for example, eukaryotes, such as humans, such as experimental subjects, or fungal cells, or from bacterial cells. ATP assays are much faster than CFU assays because they are typically based on the enzymatic production via light through the rapid enzyme luciferase. However, an inherent drawback of chemical reactions, especially biochemical reactions, is that small amounts of undesirable molecules can significantly bias the results obtained from such reactions. In practice, trace amounts of, for example, surface disinfectants can lead to misinterpretations of results obtained from ATP tests. Furthermore, samples subjected to ATP testing are damaged by contact with the chemicals required for the test and thus cannot be used for further testing. Therefore, typical equipment used for ATP testing is intended for single use only and is not designed for sample recovery, such as for additional analysis.

[0009] Typically, the test reagent is separated from the unused sample collection device (such as a swab strip) by a permeable membrane. Both the test reagent and the swab strip are usually provided in a sealed cylindrical tube or vial. To analyze the sample, the tube is opened and the sample is collected from the surface using the swab strip. The swab strip containing the sample is then reinserted into the tube and used to penetrate the membrane, bringing the sample into contact with the test reagent.

[0010] WO99 / 38996 discloses a swab strip and a corresponding housing plus suitable reagents for detecting ATP, wherein the reagents are contained in a chamber and the reagents are separated from the swab strip by a permeable membrane.

[0011] WO 2004 / 086979 A1 relates to a swab strip with a tip covered by hydrophilic fibers, the hydrophilic fibers covering the tip in the form of a layer applied by flocking.

[0012] WO 2005 / 049809 A1 relates to a method and apparatus for detecting antibiotic substances by using growth inhibition of microbial cultures.

[0013] DE 10 2012 024 353 A1 discloses a container comprising multiple chambers separated by multiple membranes, which can be penetrated by inserting a swab strip. It is proposed to transfer a sample into a liquid contained within the container chambers and analyze the sample in the liquid by light scattering measurements.

[0014] US 2015 / 0276573 A1 relates to flow cytometry methods for detecting microorganisms and discloses a swab kit for use in such methods, the kit including a housing that includes a swab strip, a filter, and a collection unit.

[0015] WO 2019 / 025613 A1 discloses a microfluidic particle analysis device suitable for rapid and direct determination of bacteria from liquid samples, independent of the culture of the collected microorganisms and any chemical reactions. However, to date, a convenient method for transferring liquid samples from containers to the analytical device and subsequently emptying the flow path included in the analytical device is not available.

[0016] To date, many flow cytometry instruments rely on a single-syringe system that penetrates a membrane covering the sample within a container. However, these systems face several challenges, such as the need for large volumes of sample liquid and the lack of suitable solutions for cleaning the instrument and associated liquid flow paths. Consequently, such systems are either not immediately reusable without additional cleaning steps or require complex architectures.

[0017] Therefore, one object of the present invention is to provide a container having a suitable architecture that allows the liquid contained in the container to be transferred to another container or instrument (e.g., an analytical device) and the liquid to be returned to the first container.

[0018] This objective is achieved by providing a container for small liquid volumes, the container having at least one inlet chamber, at least one outlet chamber, an open top, and a bottom, wherein the top is optionally provided with a removable cap element; wherein the bottom includes at least one receiving area; wherein the at least one inlet chamber is capable of receiving a swab strip; wherein the at least one inlet chamber has at least one open top and is connectable via the at least one receiving area to at least a first free end of a flow path; and wherein the at least one outlet chamber has at least one open top and is connectable via at least one receiving area to at least another free end of the flow path. By providing such a container, it becomes advantageous to establish a way for sample liquid contained in the inlet chamber of the container to enter another container, such as an instrument (e.g., an analytical device or unit), along the flow path via a connection to at least the first free end of the flow path, and return to the container via the at least other free end of the flow path, but in the at least one outlet chamber. When using the container according to the invention, the liquid contained in the container can be received and processed from both the top and bottom ends of the container. Thus, for example, a sample can be introduced into the liquid contained in the inlet chamber via the open top of the container and the open top of the inlet chamber to form a sample liquid, which can be sampled via the bottom of the container. Liquid transfer can be achieved, for example, by applying pressure or suction to one chamber of the container, thereby transporting the liquid contained in that chamber to the free end of a flow path connected to that chamber. The liquid can then be further transported along the flow path to another chamber. Back pressure or even overpressure can be avoided by providing an open top for the outlet chamber. Another non-limiting possibility for achieving liquid or fluid transfer is a pump system that pumps the liquid through components of the container and the flow path. Alternative methods of liquid transfer via flow paths are known to those skilled in the art. Once the sample liquid level is below the opening at the free end of the flow path, gas (e.g., air) is introduced into the flow path via the free end when flow is applied. This introduced gas displaces substantially all the liquid contained in the flow path until the gas exits the flow path through another free end. Ultimately, both free ends and the entire flow path from the first free end to the other are essentially emptied of sample liquid. Containers for small liquid volumes, as mentioned herein, can be, for example, sample tubes or sample dishes, essentially any container or reservoir suitable for holding liquids, preferably containing biological material, particularly biological cells. Therefore, small liquid volumes as used herein refer to liquid volumes in the milliliter range, preferably less than 100 mL, more preferably less than 50 mL, even more preferably less than 15 mL, and most preferably less than 5 mL.Furthermore, the removable cap element may include a fixing structure, such as a clamping structure, wherein the fixing structure is preferably capable of securing the swab strip. Therefore, containers for small liquid volumes, as mentioned herein, may include a removable cap element comprising a fixing structure, preferably a clamping structure, and a swab strip, wherein the swab strip is secured to the removable cap element by the fixing structure. In one embodiment, a container as described above is provided, wherein at least one inlet chamber and at least one outlet chamber are disposed adjacent to each other; and preferably, wherein the at least one inlet chamber and the at least one outlet chamber are vertically separated from each other.

[0019] In another embodiment of the invention, a container as described above is provided, wherein the volume of the at least one exit chamber is smaller than the volume of the at least one inlet chamber. Therefore, fluid having a volume substantially equal to that of at least one inlet chamber can be introduced into the inlet chamber and transported along the flow path to the at least one exit chamber without the risk of the at least one inlet chamber drying out, particularly the risk of a swab inserted into the at least one inlet chamber drying out. Due to the small diameter of typical flow path tubing, the volume of fluid contained in the flow path is generally small. In cases where there is a long flow path that can maintain a volume greater than the volume difference between the at least one inlet chamber and the at least one exit chamber, the container as described above is preferably provided, wherein the combined volume of the at least one exit chamber and the flow path is smaller than the volume of the at least one inlet chamber. It is contemplated that the volume of the at least one inlet chamber is at least 1.2 times larger, for example at least 1.5 times larger, or for example at least 1.7 times larger, or for example at least 2 times larger than the volume of the at least one exit chamber, more preferably at least 1.2 times larger, for example at least 1.5 times larger, or for example at least 1.7 times larger, or for example at least 2 times larger than the volume of the at least one exit chamber, and more preferably at least 1.2 times larger, for example at least 1.5 times larger, or for example at least 1.7 times larger, or for example at least 2 times larger than the combined volume of the flow path and the at least one exit chamber. Furthermore, when the volume of fluid to be emptied from the outlet chamber is small, the emptying of the outlet chamber can be achieved more quickly. The volume of fluid to be emptied from the outlet chamber depends on the location of the opening at the free end of the flow path within the outlet chamber and the geometry of the outlet chamber. Any volume of fluid above the liquid level at the opening at the free end of the flow path is fluid to be removed from the outlet chamber. Once the liquid level in the outlet chamber drops below the opening at the free end of the flow path, this fluid is no longer fluid to be emptied from the outlet chamber, because it is impossible to transfer this fluid to the opening at the free end of the flow path.

[0020] In another embodiment of the invention, the container as described above is provided in such a way that at least one outlet chamber is arranged to be in fluid connection with at least one inlet chamber via at least one open tip of the at least one outlet chamber. This fluid connection via at least one open tip of the at least one outlet chamber is arranged such that the direction of fluid flow from the at least one outlet chamber into the at least one inlet chamber via the at least one open tip of the at least one outlet chamber is substantially unidirectional, meaning that fluid can be transferred from the at least one outlet chamber to the at least one inlet chamber, but not vice versa. Preferably, fluid exceeding the volume of the at least one outlet chamber can flow into or be transported to the at least one inlet chamber via the at least one open tip of the at least one outlet chamber. This embodiment allows sample liquid contained in the inlet chamber of the container to be transferred via a first free end of the flow path to, for example, an analytical device, in which the sample liquid is analyzed, for example by means of flow cytometry. Once the sample has passed through the analytical component of the analytical device, the sample can be further transferred via a second free end of the flow path to the outlet chamber of the container. By providing a container as described above, wherein the volume of the outlet chamber is smaller than the volume of at least one inlet chamber; and wherein at least one outlet chamber is arranged to be fluidly connected to at least one inlet chamber via at least one open tip of said at least one outlet chamber, all sample liquid exceeding the volume of said outlet chamber can flow into said inlet chamber and thus can be directly recycled back into said inlet chamber. The recycled sample liquid can be transported again from said inlet chamber to the analytical apparatus via a flow path. Thus, the analysis of a sample liquid can be operated in a continuous flow mode, thereby improving the accuracy of the analysis. Furthermore, the entire flow path between the free ends of the flow path can be emptied by reversing the flow direction, and thus transporting all fluid to be emptied from the outlet chamber back into the inlet chamber via the free end of the flow path connected to the outlet chamber along said flow path, and further via the free end of the flow path connected to the inlet chamber. Therefore, once the sample liquid has been sufficiently analyzed, the flow path can be substantially completely emptied. Considering that such a flow path can be an external flow path that connects the container as described herein to at least one other container and / or analytical instrument, or that such a flow path can be included in another container, such as an analytical instrument, for example, the microfluidic particle analysis device disclosed in WO 2019 / 025613 A1.

[0021] In another embodiment of the invention, at least one open tip of at least one outlet chamber, which provides a fluid connection between at least one outlet chamber and at least one inlet chamber as described above, is partially covered or restricted by a covering element. This minimizes premature spillage of sample liquid into the outlet chamber, and most of the fluid is contained in the inlet chamber at least until flow begins.

[0022] In another embodiment, a container as described herein is provided, wherein at least one receiving region is at least one diaphragm; wherein when at least a first free end of the flow path is at least a first hollow needle, at least one inlet chamber is accessible by the at least first free end of the flow path through the at least one diaphragm; wherein when at least another free end of the flow path is at least another hollow needle, at least one outlet chamber is accessible by the at least another free end of the flow path through the at least one diaphragm; and wherein the at least first hollow needle is connectable to the at least other hollow needle to establish a fluid connection between the at least first hollow needle and the at least other hollow needle via the flow path. Such a container (where the receiving region is at least one diaphragm, which is permeable by at least a first hollow needle and at least another hollow needle to enter at least one inlet chamber and at least one outlet chamber, respectively) allows at least one inlet chamber and at least one outlet chamber of the container to be connected to the flow path via at least two hollow needles. In another embodiment, the outer diameter of at least the first hollow needle and at least the other hollow needle is at most 0.5 cm, for example at most 0.3 cm, or for example at most 0.2 cm, or for example at most 0.15 cm. By using hollow needles with preferably small outer diameters, damage to the diaphragm is minimized when pierced with such hollow needles.

[0023] The term "septum" as used herein can also be referred to by synonyms known to those skilled in the art, such as membrane or diaphragm. It also encompasses all elements that have substantially the same function as the septum described herein, namely, elements that provide the possibility of connecting a flow path to a container or a chamber of a container. It is understood that a container according to the invention may include not only a receiving area covering at least one inlet chamber and at least one outlet chamber, particularly a septum, but also two or more receiving areas, wherein, for example, a first septum covers at least one inlet chamber and a second septum covers at least one outlet chamber.

[0024] In another embodiment of the invention, the container described herein is provided in such a way that at least one outlet chamber includes an outer wall and an inner wall of the outlet chamber; at least one inlet chamber includes an outer wall and an inner wall of the inlet chamber; at least one inlet chamber is at least partially surrounded by at least one outlet chamber; at least one inlet chamber is formed by the inner wall of the inlet chamber and at least a portion of its bottom end; and at least one outlet chamber is formed by the inner wall of the outlet chamber, at least a portion of the outer wall of the inlet chamber, and at least a portion of its bottom end. Containers with this architecture are found to be particularly advantageous in terms of manufacturability and connectability to flow paths, for example, by connecting the container to a flow path via a hollow needle as described herein. Thus, a container is provided as described above, wherein the distance between the outer wall of at least one inlet chamber and the outer wall of at least one outlet chamber is at least 0.1 mm, for example at least 0.2 mm, or for example at least 0.3 mm, or for example at least 0.4 mm. This is taken into consideration that the distance between the outer wall of at least one inlet chamber and the outer wall of at least one outlet chamber can be achieved consistently or partially. In one embodiment, the distance is partially achieved, wherein, in addition to at least one channel structure, the distance between the outer wall of at least one inlet chamber and the outer wall of at least one outlet chamber can be partially less than 0.1 mm, wherein, in the channel structure, the distance between the outer walls of the at least one inlet chamber and the at least one outlet chamber is at least 0.1 mm, for example at least 0.2 mm, or at least 0.3 mm, or at least 0.4 mm. This avoids fluid retention due to capillary action and allows for effective emptying of the outlet chamber via the flow path. The invention also relates to a container as described herein, wherein the at least one inlet chamber is capable of containing a swab strip. The swab strips mentioned herein refer to, for example, swab strips used in the field of hygiene monitoring. By providing a container in which the inlet chamber is capable of containing a swab strip, samples collected by such swab strips can be directly and conveniently transferred to a liquid contained in the inlet chamber. Further, the container including the inlet chamber capable of containing the swab strip is arranged in such a way that the swab strip cannot contact at least a first free end of the flow path. This prevents the flow path from being blocked by the swab strip or, for example, sample components adsorbed on the swab strip. At the same time, at least the sample collection portion of the swab strip must be completely immersed in the liquid contained in at least one oral cavity chamber.

[0025] Furthermore, containers as described herein can be provided, wherein the container includes at least one bottom element that partially covers the receiving area, preferably a diaphragm. It has been found that this additional bottom element, which partially covers the receiving area, preferably a diaphragm, results in stabilization of the receiving area, thereby increasing the durability of at least one receiving area and facilitating penetration with a hollow needle when the receiving area is a diaphragm. Preferably, the bottom element includes at least two passageways. Thus, the insertion of a hollow needle can be guided to reliably and easily penetrate the diaphragm into the inlet and outlet chambers of the container.

[0026] Furthermore, consider providing a container as described herein, wherein at least one inlet chamber is divided by at least one filter into at least a first inlet sub-chamber and at least a second inlet sub-chamber, wherein the at least second inlet sub-chamber is connectable to at least a first free end of the flow path via at least one receiving area. This allows undesirable elements contained in the liquid, such as particles that could clog the flow path, to be prevented from entering the flow path. Moreover, such particles could interfere with the analytical unit and thus lead to erroneous measurements. The at least first inlet sub-chamber can directly receive the sample fluid, which must pass through at least one filter before entering the at least second inlet sub-chamber. Once the at least second inlet sub-chamber is connected to at least a first end of the flow path, the thus filtered sample fluid can be transported into the flow path.

[0027] Furthermore, containers as described herein may be provided, wherein the containers include at least one guide element. Such guide elements allow the container to be connected to the free end of a flow path or adapter, or another container or instrument including the free end of a flow path, in a specific desired orientation. This is conceived in the free end of the flow path or adapter, or other container or instrument including the free end of a flow path, which includes a mating element that mates with the guide element. In particular, this is conceived in the way that the guide element and the mating element mate together, analogous to, for example, two puzzle pieces. The guide element may be, for example, a recessed structure or a notch structure. In this case, the mating element mates with the guide element will be a protruding element that mates into the recessed or notched structure. Conversely, the guide element may also be a protruding element, such as a nose-like structure, in which case the mating element may be a recessed or notched structure.

[0028] When considering connecting two or more parts to form a system that performs the desired function, maximum compatibility is required. Therefore, another object of the present invention is to provide a kit in which the various parts are designed to achieve optimal compatibility.

[0029] This objective is achieved by providing a kit comprising a container, an analytical unit, and means for establishing a fluid connection via the analytical unit from at least one inlet chamber to at least one outlet chamber. In another embodiment, a kit as described herein is provided, wherein the means for establishing a fluid connection via the analytical unit from at least one inlet chamber to at least one outlet chamber comprises at least a first hollow needle, at least another hollow needle, and a flow path.

[0030] In another embodiment, the kit described herein further includes a swab strip. In yet another embodiment, the kit described herein further includes a fluid and / or at least one buffer component. The fluid can be any liquid suitable for containing a biological sample, such as water or a liquid buffer. The at least one buffer component can be a buffer salt. Upon addition of a liquid (e.g., water), the buffer salt can dissolve and serve as a buffer solution suitable for containing a biological sample.

[0031] Considering that, in one embodiment of the invention, a kit is provided in which the analytical unit includes means for establishing a fluid connection via the analytical unit from at least one inlet chamber to at least one outlet chamber. Therefore, substantially all parts of the means for establishing the fluid connection along the flow path via the analytical unit from at least one inlet chamber to at least one outlet chamber are part of the analytical unit, provided primarily as internal portions of the analytical unit. In such embodiments, delivery convenience is found to be maximized. The only external part of the means for establishing the fluid connection via the analytical unit from at least one inlet chamber to at least one outlet chamber is the free end of the flow path, such as a hollow needle, through which a connection between the container and the analytical unit can be easily established.

[0032] In another aspect, the present invention relates to an interface comprising a fluid container and a flow path, the interface comprising at least one inlet chamber, at least one outlet chamber, a top end, a bottom end, at least a first free end of the flow path, and at least another free end of the flow path, wherein the bottom end includes at least one receiving area; wherein the at least one inlet chamber is capable of receiving a swab strip; wherein the at least one inlet chamber has at least one open top end and is connectable via the at least one receiving area to the at least first free end of the flow path; and wherein the at least one outlet chamber has at least one open top end and is connectable via the at least one receiving area to the at least another free end of the flow path. By providing such an interface, it is surprisingly found that fluid can be transported from the inlet chamber contained in a first container via the flow path, and preferably via a second container or analytical unit or instrument, to the outlet chamber contained in the first container, and back to the inlet chamber. The delivery or transport of fluid via such an interface can be performed without fluid spillage or leakage. The fluid, as referred to herein, can be a liquid, such as an aqueous solution, suspension, oil, or gas. Preferably, the fluid is a liquid containing sample material, preferably biological material, such as biological cells.

[0033] In another embodiment, the interface as described herein is provided in a manner in which the volume of the at least one exit chamber is smaller than the volume of the at least one inlet chamber. Thus, a fluid volume corresponding to the volume of the at least one inlet chamber can be introduced into the inlet chamber and transported along the flow path to the at least one exit chamber without the risk of the at least one inlet chamber drying out. Where there is a long flow path that can maintain a volume greater than the volume difference between the at least one inlet chamber and the at least one exit chamber, it is preferable to provide the interface as described above, wherein the combined volume of the at least one exit chamber and the flow path is smaller than the volume of the at least one inlet chamber.

[0034] The invention also relates to an interface as described herein, wherein at least one exit chamber is arranged to be in fluid communication with at least one inlet chamber via at least one open tip of the at least one exit chamber. By providing such an interface, any fluid volume exceeding the volume of the exit chamber can be directly recirculated into the inlet chamber and optionally further re-enter the flow path via a first free end of the flow path.

[0035] In another embodiment, the present invention relates to an interface as described herein, wherein at least one receiving region is at least one diaphragm; wherein at least a first free end of the flow path is at least a first hollow needle; wherein at least another free end of the flow path is at least another hollow needle; wherein at least one inlet chamber is accessible by at least one hollow needle through the at least one diaphragm; wherein at least one outlet chamber is accessible by at least another hollow needle through the at least one diaphragm; and wherein the at least first hollow needle is connectable to the at least another hollow needle to establish a fluid connection between the at least first hollow needle and the at least another hollow needle via the flow path. Such an interface allows for simple and convenient connection of the container as described herein to the flow path and, for example, an analytical instrument. For example, a sample liquid to be analyzed can be provided in a container as described herein, connected to the flow path and analytical unit via the interface as described herein, analyzed by the analytical unit, and substantially completely returned to the container upon exiting the flow path, particularly with the analytical unit substantially empty and thus ready for the next analysis. To allow at least almost complete emptying of the outlet chamber through the free end of the flow path connected to the outlet chamber, it is recommended that the opening of the free end be positioned near the diaphragm.

[0036] An alternative solution that allows the flow path to be emptied is to provide a container or interface comprising only one chamber and two needles, wherein one of the needles is significantly longer than the other, such that the needle extends above the surface level of the sample fluid introduced into the chamber. Gas can then be transported back into the flow path via this long needle to displace the sample fluid. However, long needles are prone to bending, especially when reused. Stabilizing such long needles by increasing their diameter has the limitation that needles with large diameters may damage the diaphragm, leading to leakage. In another embodiment, an interface is thus provided in which the outer diameters of at least the first hollow needle and at least the other hollow needle are at most 0.5 cm, for example, at most 0.3 cm, or at most 0.2 cm, or at most 0.15 cm.

[0037] Whenever a sample is contained in a liquid to form a sample liquid, and this sample liquid is contained in a container and needs to be analyzed outside the container, such as in an analytical unit, rapid and ideally non-destructive transport from the container to the analytical unit is essential. Particularly in applications requiring the analysis of more than one sample liquid in an analytical unit, it is desirable to establish a workflow that allows for the rapid analysis of one sample liquid followed by another.

[0038] This invention achieves this objective by providing a method for analyzing a sample liquid contained in a container for a small liquid volume in at least one analytical unit; wherein the container for a small liquid volume includes at least one inlet chamber, at least one outlet chamber, a top, and a bottom, wherein the bottom includes at least one receiving area, wherein the at least one inlet chamber has at least one open top and is connectable via the at least one receiving area to at least one first free end of a flow path, and wherein the at least one outlet chamber has at least one open top and is connectable via the at least one receiving area to at least another free end of the flow path; the method includes the steps of: a) transporting the sample liquid from the at least one inlet chamber along the flow path through at least one first free end to at least one analytical unit; b) performing at least one analysis on the sample liquid in the at least one analytical unit; c) further transporting the sample liquid from the at least one analytical unit along the flow path through at least one other free end to at least one outlet chamber; d) optionally, recirculating the sample liquid from the at least one outlet chamber back to the at least one inlet chamber and repeating the preceding steps; g) returning at least one result from the analysis of the sample liquid. It has been found that by applying such a method, the sample liquid contained in the first container can be transported to and analyzed in the analytical unit, and transported back to the first container substantially without loss. The same sample liquid can be recirculated from the outlet chamber back to the inlet chamber, from which it can be transported again to the analytical unit, as described in step d). Preferably, step d) is performed by directly (i.e., without via the analytical unit) recirculating the sample liquid from at least one outlet chamber to at least one inlet chamber via at least one open tip of the at least one outlet chamber (which connects the at least one outlet chamber to at least one inlet chamber), and repeating the preceding steps. Therefore, the sample liquid can be analyzed substantially in a continuous flow mode, thereby improving analytical accuracy. To this end, the invention further relates particularly to a method by providing at least one outlet chamber, the volume of which is smaller than the volume of at least one inlet chamber; and arranging the at least one outlet chamber in fluid connection with at least one inlet chamber via at least one open tip of the at least one outlet chamber. The analytical unit as described herein can, for example, be included in a second container, device, or instrument. It is also considered that several analytical units may be provided in series and / or in parallel along the flow path. As mentioned herein, an analytical unit or instrument or device including an analytical unit may be, but is not limited to, a flow cell equipped with a detector (e.g., an optical detector, a flow cytometer, a particle analyzer, etc.).

[0039] The present invention also relates to a method for analyzing a sample liquid contained in a container for small liquid volumes as described herein, in at least one analytical unit; wherein the container for small liquid volumes includes at least one inlet chamber, at least one outlet chamber, a top end, and a bottom end, wherein the bottom end includes at least one receiving area, wherein the at least one inlet chamber has at least one open top end and is connectable via the at least one receiving area to at least a first free end of a flow path, and wherein the at least one outlet chamber has at least one open top end and is connectable via the at least one receiving area to at least another free end of the flow path; the method includes the steps of: a) transporting the sample liquid from at least one inlet chamber through at least the first free end of the flow path along the flow path to at least one analytical unit; b) performing at least one analysis on the sample liquid in the at least one analytical unit; c) transferring the sample liquid from the at least one inlet chamber to the at least one free end of the flow path to at least one analytical unit. The process includes: d) transporting the sample liquid from the at least one outlet chamber to at least one inlet chamber via at least one other free end of the flow path; g) returning at least one result from the analysis of the sample liquid; and further including the steps of: e) transporting the sample liquid from the at least one outlet chamber via at least one other free end of the flow path via at least one analytical unit and further along the flow path via at least one first free end of the flow path to at least one inlet chamber; f) transporting gas from the at least one outlet chamber via at least one other free end of the flow path via at least one analytical unit and further along the flow path via at least one first free end of the flow path to the at least one inlet chamber, thereby displacing the sample liquid from the flow path with the gas. Surprisingly, it is found that the sample liquid can be returned substantially completely to the first container, while the flow path and at least one analytical unit are substantially emptied. Therefore, another sample liquid can subsequently be analyzed via the same method without performing additional cleaning steps on the flow path or analytical unit. Liquid transport can be achieved, for example, by pumping, suction, or pressure. It has been found that by providing a method for analyzing sample liquids according to the invention, the flow path can be effectively emptied as described herein, resulting in sufficiently low residue from the first sample liquid to the second sample liquid to be analyzed without additional cleaning. It has been found that in at least one analytical unit as described above, the analyte residue is at least 20% of the analyte without performing steps e) and f) of the method for analyzing sample liquids contained in a first container as described herein.For example, suppose the first sample liquid contains 100 analyte units and the second sample liquid contains 0 analyte units. The first sample liquid correctly identifies 100 analyte units, but due to the omission of steps e) and f), 20 analyte units are incorrectly identified for the second sample liquid because 20% of the analyte remains in the measurement of the second sample liquid due to the omission of steps e) and f). In contrast, performing steps e) and f) results in analyte residues of less than 5% or even less than 2%. Therefore, the method according to the invention for analyzing sample liquids contained in a first container can be performed such that analyte residues between the first and second sample liquids are less than 5%, for example less than 2% or less than 1%, without the need for additional cleaning steps.

[0040] According to another embodiment, a method is provided for analyzing a sample liquid contained in a container for a small liquid volume, as described herein, wherein the volume of at least one outlet chamber is smaller than the volume of at least one inlet chamber; and wherein the at least one outlet chamber is arranged to be fluidly connected to the at least one inlet chamber via at least one open tip of the at least one outlet chamber. In another embodiment of the invention, a method is provided for analyzing a sample liquid contained in a container for a small liquid volume, as described herein; wherein at least a first free end of the flow path is at least a first hollow needle; wherein at least another free end of the flow path is at least another hollow needle; wherein at least one receiving region is at least one diaphragm; wherein at least one inlet chamber can be received by at least one hollow needle through the at least one diaphragm; wherein at least one outlet chamber can be received by at least another hollow needle through the at least one diaphragm; and wherein the at least first hollow needle can be connected to the at least another hollow needle to establish a fluid connection between the at least first hollow needle and the at least another hollow needle via the flow path. Thus, the method can be performed most conveniently because the connection between the inlet and outlet chambers of the container and the flow path can be easily established by penetrating the diaphragm with a needle. Liquid transport as described herein can be achieved, for example, via a pump system. The direction of liquid flow can be selected by defining the corresponding pump system. Transport of liquids (e.g., sample liquids) and / or gases can be achieved by applying, for example, suction pressure or pressure. By establishing a first flow direction, liquid can be transported along a flow path from the inlet chamber to the outlet chamber. And liquid can be transported back from the outlet chamber to the inlet chamber along a flow path by reversing the flow direction, i.e., by applying a second flow direction opposite to the first flow direction. Further, considering the optional recirculation of liquid from at least one outlet chamber to the inlet chamber as mentioned in step d) above, this can be achieved, for example, by providing an outlet chamber in a manner that provides a fluid connection between the outlet chamber and the inlet chamber via at least one open tip of at least one outlet chamber. Preferably, this fluid connection is achieved by providing an outlet chamber, wherein the volume of the outlet chamber is smaller than the volume of the inlet chamber, and wherein any liquid exceeding the volume of the outlet chamber flows into or is transported to the inlet chamber.

[0041] In particular, methods for analyzing sample liquids contained in containers, as described herein, are applied in the field of hygiene monitoring as methods for analyzing surface hygiene. In such methods for analyzing surface hygiene, a sample is obtained from the surface, for example, by using a swab or any other suitable means for obtaining a sample from the surface; the sample is transferred to a suitable liquid to provide a sample liquid; said sample liquid is then transferred to a container according to the invention and analyzed as described herein. Alternatively, the sample liquid can be provided by transferring the sample to a suitable liquid, which is provided in the container, particularly in at least one inlet chamber of the container according to the invention.

[0042] The advantage of the method for analyzing a sample liquid contained in a container as described herein in an analytical unit is that, after analysis, the container can be emptied and refilled with another sample liquid to be analyzed. Therefore, the container is envisioned to be reusable. Furthermore, or alternatively, once the sample liquid has been analyzed in a first analysis according to the method according to the invention and returned to the container, the same sample liquid can be analyzed in another analytical unit by repeating the method of the invention in that other analytical unit.

[0043] The present invention and its specific embodiments are further characterized by the following schemes: 1. A container for small liquid volumes, the container having at least one inlet chamber, at least one outlet chamber, an open top, and a bottom, wherein the top has a removable cap element; wherein the bottom includes at least one receiving area; wherein the at least one inlet chamber has at least one open top and is connectable via the at least one receiving area to at least a first free end of a flow path; and wherein the at least one outlet chamber has at least one open top and is connectable via the at least one receiving area to at least another free end of the flow path.

[0044] 2. The container according to Scheme 1, wherein the volume of the at least one outlet chamber is smaller than the volume of the at least one inlet chamber.

[0045] 3. The container according to claim 2, wherein the volume of the at least one inlet chamber is at least 1.2 times larger than the volume of the at least one outlet chamber, for example at least 1.5 times larger, or for example at least 1.7 times larger, or for example at least 2 times larger.

[0046] 4. The container according to any one of claims 2 and 3, wherein the at least one outlet chamber is arranged to be in fluid connection with the at least one inlet chamber via the at least one open tip of the at least one outlet chamber.

[0047] 5. The container according to claim 4, wherein the size of the at least one open top of the at least one outlet chamber is partially limited by the covering element.

[0048] 6. The container according to any one of claims 1 to 5, wherein the at least one receiving area is at least one diaphragm; wherein at least a first free end of the flow path is at least a first hollow needle; wherein at least another free end of the flow path is at least another hollow needle; wherein at least one inlet chamber can be received by the at least one hollow needle through the at least one diaphragm; wherein at least one outlet chamber can be received by the at least another hollow needle through the at least one diaphragm; and wherein the at least one hollow needle can be connected to the at least another hollow needle to establish a fluid connection between the at least one hollow needle and the at least another hollow needle via the flow path.

[0049] 7. The container according to claim 6, wherein the outer diameter of the at least first hollow needle and the at least other hollow needle is at most 0.5 cm, for example at most 0.3 cm, or for example at most 0.2 cm, or for example at most 0.15 cm.

[0050] 8. The container according to any one of claims 6 to 7, wherein the container further comprises at least one bottom element, wherein the at least one bottom element partially covers the diaphragm.

[0051] 9. The container according to claim 8, wherein the at least one bottom element includes at least two passages.

[0052] 10. The container according to any one of claims 1 to 9, wherein the container includes at least one guide element.

[0053] 11. The container according to any one of claims 1 to 10, wherein the at least one outlet chamber includes an outer wall of the outlet chamber and an inner wall of the outlet chamber; wherein the at least one inlet chamber includes an outer wall of the inlet chamber and an outer wall of the inlet chamber; wherein the at least one inlet chamber is at least partially surrounded by the at least one outlet chamber; wherein the at least one inlet chamber is formed by the inner wall of the inlet chamber and at least a portion of the bottom end; and wherein the at least one outlet chamber is formed by the inner wall of the outlet chamber, at least a portion of the outer wall of the inlet chamber, and at least a portion of the bottom end.

[0054] 12. The container according to any one of claims 1 to 11, wherein the at least one inlet chamber is divided by at least one filter element into at least a first inlet sub-chamber and at least a second inlet sub-chamber, wherein the at least second inlet sub-chamber is connectable to the at least first free end of the flow path via the at least one contact area.

[0055] 13. The container according to any one of claims 1 to 12, wherein the at least one oral cavity is capable of containing a swab strip.

[0056] 14. The container according to any one of claims 1 to 13, wherein the container is a sample tube.

[0057] 15. A kit comprising a container according to any one of claims 1 to 14, an analysis unit, and means for establishing a fluid connection via the analysis unit from the at least one inlet chamber to the at least one outlet chamber.

[0058] 16. The kit according to claim 15, wherein the kit further comprises at least one swab strip.

[0059] 17. The kit according to any one of claims 15 and 16, wherein the kit further comprises at least one fluid or buffer component.

[0060] 18. The kit according to any one of claims 15 to 17, wherein the means for establishing a fluid connection from the at least one inlet chamber to the at least one outlet chamber via the analysis unit comprises the at least first hollow needle, the at least another hollow needle, and the flow path.

[0061] 19. The kit according to any one of claims 15 to 18, wherein the analysis unit includes means for establishing a fluid connection from the at least one inlet chamber to the at least one outlet chamber via the analysis unit.

[0062] 20. An interface for fluid transport, the interface comprising at least one inlet chamber, at least one outlet chamber, a top end, a bottom end, at least a first free end of a flow path, and at least another free end of the flow path, wherein the bottom end includes at least one receiving region; wherein the at least one inlet chamber has at least one open top end and is connectable to at least the first free end of the flow path via the at least one receiving region; and wherein the at least one outlet chamber has at least one open top end and is connectable to at least the other free end of the flow path via the at least one receiving region.

[0063] 21. The interface according to claim 20, wherein the volume of the at least one exit chamber is smaller than the volume of the at least one inlet chamber.

[0064] 22. The interface according to claim 21, wherein the at least one exit chamber is arranged to be fluidly connected to the at least one inlet chamber via the at least one open tip of the at least one exit chamber.

[0065] 23. The interface according to any one of claims 20 to 22, wherein the at least one inlet chamber is divided by at least one filter into at least a first inlet sub-chamber and at least a second inlet sub-chamber, wherein the at least second inlet sub-chamber is connectable to the at least first free end of the flow path via the at least one access region.

[0066] 24. The interface according to any one of claims 20 to 23, wherein the at least one receiving area is at least one diaphragm; wherein the at least first hollow needle is the at least first free end of the flow path; wherein the at least another hollow needle is the at least another free end of the flow path; wherein the at least one inlet chamber is accessible by the at least first hollow needle through the at least one diaphragm; wherein the at least one outlet chamber is accessible by the at least another hollow needle through the at least one diaphragm; and wherein the at least first hollow needle is connectable to the at least another hollow needle to establish a fluid connection between the at least first hollow needle and the at least another hollow needle via the flow path.

[0067] 25. The interface according to any one of claims 20 to 24, wherein the at least one inlet oral chamber is capable of accommodating at least one swab strip.

[0068] 26. A method for transporting liquid, particularly a small volume of liquid, from a first container to a second container and back to the first container, wherein the first container includes at least one inlet chamber, at least one outlet chamber, a top end, and a bottom end, wherein the bottom end includes at least one receiving region, wherein the at least one inlet chamber has at least one open top end and is connectable via the at least one receiving region to a first free end of a flow path, and wherein the at least one outlet chamber has at least one open top end and is connectable via the at least one receiving region to at least another free end of the flow path; the method comprising the steps of: a) transporting liquid from the at least one inlet chamber through the at least one first free end of the flow path along the flow path via the second container a) Transporting the liquid from the at least one outlet chamber to the at least one inlet chamber via the at least one other free end of the flow path; b) Optionally, recirculating the liquid directly from the at least one outlet chamber to the at least one inlet chamber; c) Transporting the liquid from the at least one outlet chamber along the flow path via the second container and through the at least one free end of the flow path to the at least one inlet chamber via the at least one other free end of the flow path; d) Transporting gas from the at least one outlet chamber along the flow path via the second container and through the at least one free end of the flow path to the at least one inlet chamber, thereby displacing the liquid from the flow path with the gas.

[0069] 27. The method according to claim 26, wherein the volume of the at least one exit oral cavity is smaller than the volume of the at least one in oral cavity; and wherein the at least one exit oral cavity is arranged to be in fluid connection with the at least one in oral cavity via the at least one open tip of the at least one exit oral cavity.

[0070] 28. The method according to any one of claims 26 and 27, wherein the at least first free end of the flow path is at least a first hollow needle; wherein the at least other free end of the flow path is at least another hollow needle; and wherein the at least one receiving region is at least one diaphragm; wherein the at least one inlet chamber is receptable by the at least first hollow needle through the at least one diaphragm; wherein the at least one outlet chamber is receptable by the at least another hollow needle through the at least one diaphragm; and wherein the at least first hollow needle is connectable to the at least another hollow needle to establish a fluid connection between the at least first hollow needle and the at least another hollow needle via the flow path.

[0071] 29. A method for analyzing a sample liquid contained in a first container according to any one of claims 1 to 14 in at least one analytical unit; the method comprising the steps of: a) transporting the sample liquid from at least one inlet chamber through at least one first free end of the flow path to the at least one analytical unit; b) performing at least one analysis on the sample liquid in the at least one analytical unit; c) further transporting the sample liquid from the at least one analytical unit along the flow path through at least one other free end of the flow path to the at least one outlet chamber; d) optionally, recirculating the sample liquid from the at least one outlet chamber to the at least one inlet chamber and repeating the preceding steps; g) returning at least one result from the analysis of the sample liquid.

[0072] 30. The method according to claim 29, wherein the volume of the at least one exit oral cavity is smaller than the volume of the at least one in oral cavity; and wherein the at least one exit oral cavity is arranged to be in fluid connection with the at least one in oral cavity via the at least one open tip of the at least one exit oral cavity.

[0073] 31. The method according to any one of claims 29 and 30, the method further comprising the steps of: e) transporting the sample liquid from the at least one outlet chamber through the at least other free end of the flow path along the flow path via the analytical unit and further along the flow path through the at least first free end of the flow path to the at least one inlet chamber; and f) transporting gas from the at least one outlet chamber through the at least other free end of the flow path along the flow path via the analytical unit and further along the flow path through the at least first free end of the flow path to the at least one inlet chamber, thereby displacing the sample liquid from the flow path with the gas.

[0074] 32. The method according to any one of claims 29 to 31, wherein the at least first free end of the flow path is at least a first hollow needle; wherein the at least other free end of the flow path is at least another hollow needle; wherein the at least one receiving region is at least one diaphragm; wherein the at least one inlet chamber can be received by the at least first hollow needle through the at least one diaphragm; wherein the at least one outlet chamber can be received by the at least another hollow needle through the at least one diaphragm; and wherein the at least first hollow needle can be connected to the at least another hollow needle to establish a fluid connection between the at least first hollow needle and the at least another hollow needle via the flow path.

[0075] 33. A method for analyzing surface hygiene, the method comprising the steps of: a) providing a container and an analytical unit according to any one of claims 1 to 14; b) sampling from a surface; c) providing a sample liquid by transferring the sample into a liquid in the at least one inlet chamber; d) transporting the sample liquid from the at least one inlet chamber along the flow path through the at least first free end of the flow path to the at least one analytical unit; e) performing at least one analysis on the sample liquid in the at least one analytical unit; f) further transporting the sample liquid from the at least one analytical unit along the flow path through the at least another free end of the flow path to the at least one outlet chamber; g) optionally, recirculating the sample liquid from the at least one outlet chamber back to the at least one inlet chamber and repeating the preceding steps; j) returning at least one result from the analysis of the sample liquid.

[0076] 34. The method according to claim 33, wherein the volume of the at least one exit oral cavity is smaller than the volume of the at least one in oral cavity; and wherein the at least one exit oral cavity is arranged to be in fluid connection with the at least one in oral cavity via the at least one open tip of the at least one exit oral cavity.

[0077] 35. The method according to any one of claims 33 and 34, the method further comprising the steps of: h) transporting the sample liquid from the at least one outlet chamber through the at least other free end of the flow path along the flow path via the analytical unit and further along the flow path through the at least first free end of the flow path to the at least one inlet chamber; and i) transporting gas from the at least one outlet chamber through the at least other free end of the flow path along the flow path via the analytical unit and further along the flow path through the at least first free end of the flow path to the at least one inlet chamber, thereby displacing the sample liquid from the flow path with the gas.

[0078] 36. The method according to any one of claims 33 to 35, wherein the at least first free end of the flow path is at least a first hollow needle; wherein the at least other free end of the flow path is at least another hollow needle; wherein the at least one receiving region is at least one diaphragm; wherein the at least one inlet chamber can be received by the at least first hollow needle through the at least one diaphragm; wherein the at least one outlet chamber can be received by the at least another hollow needle through the at least one diaphragm; and wherein the at least first hollow needle can be connected to the at least another hollow needle to establish a fluid connection between the at least first hollow needle and the at least another hollow needle via the flow path.

[0079] 37. Use of the container according to any one of claims 1 to 14 in the method according to any one of claims 26 to 36.

[0080] 38. Use of the container according to any one of claims 1 to 14 in a method for determining the presence of biological cells contained in a liquid.

[0081] The solution of the present invention will be further illustrated below with reference to non-limiting drawings and embodiments.

[0082] Figure 1 This is a longitudinal sectional view of a container according to the present invention, including an interface according to the present invention.

[0083] Figure 2 This is a longitudinal sectional view of a container according to the present invention, including an interface according to the present invention.

[0084] Figure 3 This is an exploded view of the container and swab strip according to the present invention. Detailed Implementation

[0085] Figures 1 to 3 The containers or schemes thereof, including interfaces according to the present invention, shown and described below are used as illustrative embodiments only and should not be construed as limiting the implementation of the invention. Reference numerals are always used for the features indicated.

[0086] Figure 1 This is a longitudinal sectional view of a schematic container 1 according to the present invention, the container including an inlet chamber 2 with an open top 11a, an outlet chamber 3 with an open top 11b, an open top 4 of the container 1, a bottom end 5, a receiving area 7, a guide element 20, and a removable cover element 6. A first free end 8 of a flow path 9, including a second container 17, and a second free end 10 of the flow path 9 are also shown. Figure 1 In an exemplary embodiment of the container according to the invention, the first free end 8 of the flow path 9 is fluidly connected to the inlet chamber 2, and the second free end 10 of the flow path 9 is fluidly connected to the outlet chamber 3. The flow path 9 provides fluid connection between the inlet chamber 2 via the first free end 8 and the outlet chamber 3 via the second free end 10 to a second container 17, which is part of the flow path 9 and may be, for example, an analytical unit.

[0087] The container 1 containing the sample liquid 18 allows the sample liquid 18 to be transported from the inlet chamber 2 along the flow path 9 via a first free end 8 to a second container 17, which may be an analytical unit that allows analysis of the sample liquid 18 to be performed, for example by transporting the sample liquid 18 through a flow cell included in the analytical unit. The sample liquid 18 can then be further transported along the flow path 9 via a second free end 10 to the outlet chamber 3. The flow path guiding through the second container 17 (e.g., the analytical unit, such as the flow cell) is considered part of the flow path 9.

[0088] By providing such Figure 1 The exemplary container 1, including at least one receiving area 7, allows for a particularly easy connection to the flow path 9 as described herein. The interface between container 1 and flow path 9, as disclosed herein, allows for quick connection to sample dishes or containers, for example, containing sample liquids to be analyzed by the analytical unit. The free ends 8, 10 of flow path 9 may be hollow needles, and at least one receiving area 7 may be at least one diaphragm. Preferably, the free ends 8, 10 of flow path 9 are inserted into or connected in a certain way to inlet chamber 2 and outlet chamber 3, with the open ends near the bottom of inlet chamber 2 and outlet chamber 3. Thus, a majority of the sample liquid 18 contained in any of the chambers can be removed from the chamber, for example, by applying pressure. In such embodiments of the invention, it becomes possible, for example, to connect a first sample liquid contained in a first container to an analytical unit for analyzing the first sample liquid via the flow path. After emptying flow path 9, a second sample liquid contained in a second container can be directly connected to the analytical unit via the flow path without intermediate cleaning steps, thereby saving processing time, particularly when a large number of analyses must be performed. Nevertheless, a container holding, for example, a separate cleaning solution can be connected to the flow path 9 to more thoroughly clean the flow path 9 and / or at least a second container 17, which is also part of the flow path 9. Due to the specific architecture of the container according to the invention, removal of the cleaning solution from the flow path can also be easily achieved. Furthermore, this container architecture allows the use of short needles as connecting devices at the free ends 8, 10 of the flow path 9; these short needles are not easily damaged by bending and can be reused multiple times, nor are they prone to leakage after penetrating the diaphragm.

[0089] exist Figure 1In the container 1 schematically shown, the volume of the outlet chamber 3 is smaller than that of the inlet chamber 2. Sample liquid 18 exceeding the volume of the outlet chamber 3 can be recycled back directly to the inlet chamber 2 through the open tip 11b of the outlet chamber 3 by continuing to flow from the inlet chamber 2 through the flow path 9 to the outlet chamber 3. This recycled sample liquid 18 can re-enter the flow path 9 from the inlet chamber 2 through the first free end 8 of the flow path 9, and can subsequently re-enter the second container 17, whereby the recycled sample liquid 18 can be analyzed, for example, for another period of time, thereby improving analytical accuracy.

[0090] To empty the sample liquid 18 from flow path 9, the flow direction can be reversed. Thus, the sample liquid 18 contained in the outlet chamber 3 can be transported back to the inlet chamber 2 via the second free end 10 of flow path 9, along the flow path, and ultimately via the first free end 8 of flow path 9. Once the level of sample liquid 18 in the outlet chamber 3 drops below the second free end 10 of flow path 9, no more sample liquid 18 can be introduced into flow path 9 via the second free end 10. Nevertheless, by continuing flow, gas can be introduced from the outlet chamber 3 into flow path 9 via the second free end 10 and transported along flow path 9 until the gas is transported to the inlet chamber 2. Thus, the gas will have displaced substantially all of the sample liquid 18 previously contained in flow path 9. Therefore, flow path 9 can be connected to another container, for example, containing another sample fluid intended to be transported to a second container 17, for example, for analysis.

[0091] To prevent the sample liquid 18 contained in container 1 from spilling or to allow for the safe storage of sample liquid 18, it is recommended to provide a removable cap element 6. The removable cap element 6 can be used both when container 1 is connected to flow path 9 and when container 1 is not connected to flow path 9.

[0092] Figure 1The container 1, schematically shown, further includes a guide element 20. Considering that the flow path 9 can be arranged inside the second container 17, essentially only at least a first free end 8 and at least a second free end 10 of the flow path 9 are directly accessible or even visible without disassembling the second container 17. To establish connections between the flow path 9 and the inlet chamber 2 and outlet chamber 3 of the container 1, the first free end 8 of the flow path 9 needs to connect to the inlet chamber 2, and the second free end 10 of the flow path 9 needs to connect to the outlet chamber 3. To achieve these connections via the access area 7 of the container 1, it is desirable to guide the inlet chamber 2 to the first free end 8 of the flow path 9 and the outlet chamber 3 to the second free end 10 of the flow path. The guide element 20 (which may be, for example, a nose-like structure or a recess or notch structure fitted to a mating member included by the second container 17) is considered to achieve this purpose.

[0093] Figure 2 This is a longitudinal sectional view of another embodiment of the container 1 of the present invention. Figure 2 In the embodiment of the container 1 shown according to the invention, the inlet chamber 2 is considered to be surrounded by the outlet chamber 3. In this embodiment, the inlet chamber 2 is formed by the inner wall 15 of the inlet chamber and the portion of the bottom end 5 of the container 1 including the receiving area 7. The outlet chamber 3 is formed by the inner wall 13 of the outlet chamber, the outer wall 12 of the outlet chamber, and the portion of the bottom 5 of the container 1 including the receiving area 7. In this embodiment, the outer wall 14 of the inlet chamber may be the same wall as the inner wall 13 of the outlet chamber, such as... Figure 2 As shown in the example.

[0094] Figure 2 The container 1, schematically shown, further includes a filter element 22 that divides the inlet chamber 2 into a first inlet sub-chamber 2a and a second inlet sub-chamber 2b. Thus, particles that may be contained in the sample fluid 18 can be captured by the filter element 22 and retained in the first inlet sub-chamber 2a, thereby preventing such particles from ultimately entering the flow path 9 or even clogging the flow path. Figure 2 The container 1 shown includes two separate receiving areas 7, one receiving area 7 for connecting the inlet oral chamber 2, in particular the second inlet sub-chamber 2b, to the first free end 8 of the flow path 9, and the other receiving area 7 for connecting the outlet oral chamber 3 to the second free end 10 of the flow path 9.

[0095] To stabilize the bottom end 5 of container 1, which includes at least one receiving area 7, Figure 2 The container 1 shown further includes a bottom element 19, which includes a passage 23 that allows a connection to be established between a first free end 8 and an inlet chamber 2 and a second free end 10 and an outlet chamber 3.

[0096] in addition, Figure 2 The illustrative container 1 shown further includes a covering element 21 to provide spill protection to the outlet chamber 3 while still maintaining the open top 11b of the outlet chamber 3 to allow the sample liquid 18 to flow from the outlet chamber 3 to the inlet chamber 2. The covering element 21 can also be provided in an angled orientation to directly guide the sample liquid 18 introduced into such a container 1 into the inlet chamber 2.

[0097] Reference Figure 3 An exploded view of another embodiment of the container 1 according to the invention is shown. The receiving region 7 is a diaphragm, and the first free end 8 and the other free end 10 of the flow path 9 are hollow needles. In this embodiment, the inlet chamber 2 and the outlet chamber 3 are formed by combining three tube structures 24 to 26, wherein the first tube structure 24 includes a filter element 22 and a portion of the receiving region 7, and wherein this first tube structure defines a second inlet sub-chamber 2b; wherein the second tube structure 25 surrounds the first tube structure 24 and includes the first inlet sub-chamber 2a; and wherein the third tube structure 26 surrounds both the first tube structure 24 and the second tube structure 25, and wherein the third tube structure 26 includes at least a portion of the outlet chamber 3. Consideration is that the oral cavity 3 can be provided as two outlet sub-cavities, wherein the first outlet sub-cavity is provided next to and surrounded by the second inlet sub-cavity 2b by the second tube structure 25, and wherein the second outlet sub-cavity is provided, for example, by connecting the second tube structure 25 to the third tube structure 26, wherein the first outlet sub-cavity and the second outlet sub-cavity are fluidly connected to each other, and wherein the second outlet sub-cavity is fluidly connected to the inlet cavity 2 via the open tip (11b) of the second outlet sub-cavity. The sample liquid 18 transported to the first outlet sub-cavity via the second free end 10 of the flow path 9 can be further transported to the second outlet cavity and then recirculated back to the inlet cavity 2 via the open tip (11b) of the second outlet sub-cavity.

[0098] Figure 3 The diagram also shows a swab strip 16, which can be accommodated in the inlet chamber 2, particularly in the first inlet sub-chamber 2a. The swab strip 16 can be secured in a fixing structure 27 included in the removable cover element 6. Using this embodiment of the invention, the most important components for surface hygiene monitoring—the swab strip for obtaining samples and the container for holding the samples until analysis—can be provided in a convenient and practical format.

Claims

1. A container (1) for small liquid volumes, the container having at least one inlet chamber (2) with a height greater than its width, at least one outlet chamber (3), an open top (4), and a bottom (5). The top end (4) is optionally provided with a removable cover element (6). The bottom end (5) includes at least one receiving area (7). The at least one oral cavity (2) therein is capable of accommodating the swab strip (16); The at least one inlet chamber (2) has at least one open tip (11a) and is connected via the at least one receiving region (7) to at least one first free end (8) of the flow path (9); and The at least one outlet chamber (3) has at least one open top (11b) and is connected to at least another free end (10) of the flow path (9) via the at least one receiving area (7). in, The flow path (9) connects the inlet chamber and the outlet chamber.

2. The container according to claim 1, wherein a second container (17) is present, the second container (17) being part of the flow path (9).

3. The container according to claim 2, wherein the second container is one or more analysis units, the one or more analysis units being connected in series or in parallel along the flow path.

4. The container according to claim 3, wherein one or more analysis units include flow cells.

5. The container (1) according to any one of the preceding claims, wherein the volume of the at least one exit chamber (3) is smaller than the volume of the at least one inlet chamber (2).

6. The container (1) according to any one of claims 1-4, wherein the at least one outlet chamber (3) is arranged to be in fluid connection with the at least one inlet chamber (2) via the at least one open tip (11b) of the at least one outlet chamber (3).

7. The container (1) according to any one of claims 1-4, wherein the at least one receiving area (7) is at least one diaphragm; When at least the first free end (8) of the flow path (9) is at least the first hollow needle, the at least one inlet chamber (2) is received by the at least one diaphragm from the at least first free end (8) of the flow path (9). When at least one other free end (10) of the flow path (9) is at least one other hollow needle, the at least one outlet chamber (3) is received by the at least one diaphragm from the at least one other free end (10) of the flow path (9).

8. The container (1) according to any one of claims 1-4, wherein the at least one outlet chamber (3) comprises an outer wall (12) of the outlet chamber and an inner wall (13) of the outlet chamber. The at least one oral cavity (2) includes an outer wall (14) and an inner wall (15) of the oral cavity. The at least one inlet chamber (2) is at least partially surrounded by the at least one outlet chamber (3); The at least one inlet chamber (2) is formed by at least a portion of the inner wall (15) of the inlet chamber and the bottom end (5); and The at least one exiting oral cavity (3) is formed by at least a portion of the inner wall (13) of the exiting oral cavity, at least a portion of the outer wall (14) of the inlet oral cavity, and at least a portion of the bottom end (5).

9. A kit comprising a container (1) according to any one of the preceding claims, an analysis unit, and means for establishing a fluid connection via the analysis unit from the at least one inlet chamber (2) to the at least one outlet chamber (3).

10. The kit of claim 9, wherein the means for establishing a fluid connection via the analysis unit from the at least one inlet chamber (2) to the at least one outlet chamber (3) comprises at least a first hollow needle, at least another hollow needle, and a flow path (9), wherein, At least the first free end (8) of the flow path (9) is at least the first hollow needle and at least the other free end (10) of the flow path (9) is at least the other hollow needle.

11. The kit of claim 9 or 10, wherein the analysis unit comprises a flow cell.

12. A method for analyzing a sample liquid (18) contained in a container (1) for a small liquid volume in at least one analytical unit; The container (1) for small liquid volumes includes at least one inlet chamber (2), at least one outlet chamber (3), a top (4), and a bottom (5), wherein the bottom (5) includes at least one receiving area (7), wherein the at least one inlet chamber (2) has at least one open top (11a) and is connected to at least one first free end (8) of the flow path (9) via the at least one receiving area (7), and wherein the at least one outlet chamber (3) has at least one open top (11b) and is connected to at least another free end (10) of the flow path (9) via the at least one receiving area (7). The method includes the following steps: a) The sample liquid (18) is transported from the at least one inlet chamber (2) through the at least one first free end (8) of the flow path (9) to the at least one analytical unit; b) Perform at least one analysis on the sample liquid (18) in the at least one analytical unit; c) The sample liquid (18) is further transported from the at least one analytical unit along the flow path (9) through the at least other free end (10) of the flow path (9) to the at least one outlet chamber (3). d) Optionally, the sample liquid (18) is recirculated from the at least one exit chamber (3) to the at least one inlet chamber (2) and the preceding steps are repeated; g) Return at least one result from the analysis of the sample liquid (18).

13. The method according to claim 12, further comprising the following steps: e) The sample liquid (18) is transported from the at least one exit chamber (3) through the at least one other free end (10) of the flow path (9) via the flow path (9) via at least one analytical unit and further along the flow path (9) through the at least one first free end (8) of the flow path (9) to the at least one inlet chamber (2). f) The gas is transported from the at least one exit chamber (3) through the at least one other free end (10) of the flow path (9) along the flow path (9) via the at least one analytical unit and further along the flow path (9) through the at least one first free end (8) of the flow path (9) to the at least one inlet chamber (2), thereby displacing the sample liquid (18) from the flow path (9) with the gas.

14. The method according to any one of claims 12 and 13, wherein the volume of the at least one exit oral cavity (3) is smaller than the volume of the at least one in oral cavity (2); and wherein the at least one exit oral cavity (3) is arranged to be in fluid connection with the at least one in oral cavity (2) via the at least one open tip (11b) of the at least one exit oral cavity (3).

15. The method according to claim 12 or 13, wherein the at least first free end (8) of the flow path (9) is at least a first hollow needle; The at least other free end (10) of the flow path (9) is at least another hollow needle; The at least one receiving area (7) is at least one diaphragm. The at least one inlet chamber (2) is accessed by the at least one first hollow needle through the at least one septum; The at least one outlet chamber (3) is received by the at least one other hollow needle through the at least one septum; and The at least first hollow needle is connected to the at least other hollow needle to establish a fluid connection between the at least first hollow needle and the at least other hollow needle via the flow path (9).

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