WO2018153958A1 - Microfluidic test system, sample plug with sample recesses and related method - Google Patents

Abstract

A microfluidic test system comprising a microfluidic test device and a sample plug is disclosed together with a method of operating a microfluidic test system. The sample plug extends along an axis and having a first end with a first end surface and comprising a sample part and a handle part, the sample part comprising a first sample recess and a second sample recess formed in the first end surface for feeding a sample into a sample inlet of the microfluidic test device.

Description

MICROFLUIDIC TEST SYSTEM, SAMPLE PLUG WITH SAMPLE RECESSES AND RELATED METHOD

The present disclosure relates to a microfiuidic test system comprising a sample plug and a microfiuidic test device, in particular a microfiuidic test device for testing body fluids, such as urine and/or blood. Further, a sample plug for a microfiuidic test system and a method of operating a microfiuidic test system is disclosed.

BACKGROUND

Developments within medical testing has increasingly been focusing on moving testing towards the user, also known as point-of-care-testing (POCT). The traditional diagnosis of e.g. infections typically involves collection of a sample. Most modern laboratories still use traditional testing methods such as cell culture and antigen based detection. The cell culture method is highly specific, but has very low sensitivity, is expensive, slow (takes days) and requires special sample collection, storage and transport. Immunological assays like the enzyme immunoassay and direct fluorescent antibody (DFA) assay have low sensitivity and specificity as a cell culture method, which limits the use of these tests in diagnostic field.

As an alternative to the traditional laboratory methods, nucleic acid amplification tests (NAATs) were developed allowing detection of e.g. pathogen-specific DNA or RNA sequences. These tests are significantly more sensitive because they can detect as little as single nucleic acid copy of the target.

There are several drawbacks to these types of methods, including that they cannot be used by individuals without expertise within the field or without the use of for example a PCR machine or sample preparation.

However, the complexity of test methods has been and is still setting barriers for their application in POCT.

SUMMARY

It is therefore clear that there is a need for tests that requires little or no sample preparation, a simple test setup, and little or no expertise within the technical field. Such test could for example be an over the counter do-it-yourself kit.

Further, there is a need for providing a microfiuidic test system that is easy to use and error-proof.

A sample plug for a microfiuidic test system comprising a microfiuidic test device and the sample plug is disclosed, the sample plug extending along an axis and having a first end with a first end surface and comprising a sample part and a handle part. The sample part comprises a first sample recess or channel formed in the first end surface. The sample plug optionally comprises a sealing part with a sealing surface for forming a seal with a sample inlet of the microfluidic test device when the sample plug is inserted into the microfluidic test device. The sample part optionally comprises a second sample recess formed in the first end surface.

Further, a microfluidic test system comprising a microfluidic test device and a sample plug is disclosed, the microfluidic test device comprising a body; a first chamber having an outlet and holding a first buffer having a first buffer volume; a primary reaction chamber; a sample inlet for receiving a sample and being configured for feeding a sample having a sample volume into the medical test device; a first fluid path connecting the outlet of the first chamber and the sample inlet; and a second fluid path connecting the sample inlet and the primary reaction chamber, wherein the sample plug extends along an axis and having a first end with a first end surface and comprising a sample part and a handle part, the sample part comprising a first sample recess formed in the first end surface. The sample plug optionally comprises a sealing part with a sealing surface for forming a seal with the sample inlet of the microfluidic test device when the first end of the sample plug is inserted into the sample inlet. The sample part optionally comprises a second sample recess formed in the first end surface.

Further, a microfluidic test system comprising a microfluidic test device as described herein and a sample plug as described herein is disclosed. Also disclosed is a microfluidic test device.

Also disclosed is a method of operating a microfluidic test system comprising a microfluidic test device, e.g. as described herein, and a sample plug, e.g. as described herein, the method comprising sampling a sample with the sample plug; inserting the sample plug into a sample inlet of the microfluidic test device, optionallly to form a seal between the sample plug and the sample inlet and/or for feeding a sample into the sample inlet; and flushing the sample plug, e.g. first sample recess and/or second sample recess of the sample plug, with first buffer stored in a first chamber of the microfluidic test device.

A microfluidic test device is disclosed, the microfluidic test device comprising a body; a first chamber having an outlet optionally provided with a first valve and holding a first buffer having a first buffer volume; and a primary reaction chamber. The microfluidic test device comprises a sample inlet for receiving a sample and being configured for feeding a sample having a sample volume, into the medical test device; a first fluid path connecting the outlet of the first chamber and the sample inlet; and a second fluid path connecting the sample inlet and the primary reaction chamber. Further, exemplary microfluidic test device(s) comprises a primary test part comprising a primary test chamber; a third primary fluid path connecting the primary reaction chamber and the primary test part; a primary valve arranged in the third primary fluid path; and a flow driving device configured to move fluid from the primary reaction chamber to the primary test part. The microfluidic test device optionally comprises a heating assembly configured to heat a reaction fluid in the primary reaction chamber.

It is an important advantage of the present disclosure, in particular the sample plug and/or microfluidic test device, that precise, error-safe and/or simple sample taking and sample transfer/introduction is provided for.

It is an important advantage of the present disclosure that complex tests, such as LAMP tests are enabled in a point of care test device. Further, the present disclosure enables error-safe testing by implementation of a plurality of tests in the same device and performed on the same sample.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present invention will become readily apparent to those skilled in the art by the following detailed description of exemplary embodiments thereof with reference to the attached drawings, in which :

Fig. 1 schematically illustrates an exemplary microfluidic test device,

Fig. 2 is a schematic cross-sectional view of an exemplary microfluidic test device,

Fig. 3 schematically illustrates an exemplary microfluidic test device,

Fig. 4 is a perspective view of exemplary microfluidic test device,

Fig. 5 is another perspective view of exemplary microfluidic test device,

Fig. 6 is a perspective view of exemplary body of microfluidic test device,

Fig. 7 is another perspective view of exemplary body of microfluidic test device,

Fig. 8 is a second (bottom) view of exemplary body of microfluidic test device,

Fig. 9 is a cut out view of exemplary microfluidic test device,

Fig. 10 is a second (bottom) view of exemplary body of microfluidic test device,

Fig. 11 is a first end view of a first part of an exemplary sample plug, Fig. 12 is a side view of a first part of an exemplary sample plug,

Fig. 13 is a side of a first part of an exemplary sample plug,

Fig. 14 is a perspective view of a first part of an exemplary sample plug,

Fig. 15 is a first end view of a first part of an exemplary sample plug,

Fig. 16 is a cut-away view of a sample plug inserted into a body of a microfluidic test device,

Fig. 17 is a flow-chart of an exemplary method of operating a microfluidic test

system, and

Fig. 18 schematically illustrates a microfluidic test system.

DETAILED DESCRIPTION

Various exemplary embodiments and details are described hereinafter, with reference to the figures when relevant. It should be noted that the figures may or may not be drawn to scale and that elements of similar structures or functions are represented by like reference numerals throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the embodiments. They are not intended as an exhaustive description of the invention or as a limitation on the scope of the invention. In addition, an illustrated embodiment needs not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated, or if not so explicitly described.

The microfluidic test device/system may be a point-of-care (POC) microfluidic test device/system. Point-of-care testing (POCT), or bedside testing is defined as medical diagnostic testing at or near the point of care - that is, at the time and place of patient care. This contrasts with the historical pattern in which testing was wholly or mostly confined to the medical laboratory, which entailed sending off specimens away from the point of care and then waiting hours or days to learn the results, during which time care must continue without the desired information. Point-of-care tests are simple medical tests that can be performed at the bedside.

The sample plug extends along an axis and having a first end with a first end surface.

The sample plug comprises one or more sample recesses formed in the first end surface, the one or more sample recesses comprising a first sample recess in the first end surface and/or a second sample recess in the first end surface. A sample plug with a plurality of sample recesses may provide a more precise sample volume in limited cross-sectional area with a given viscosity of the sample, for example when the sample is a (optionally diluted) urine sample. Further, a sample plug with a plurality of sample recesses may enable a more controlled fluid flow in the microfluidic test device.

A sample recess, such as the first sample recess and/or the second sample recess, may extend from a circumference of the sample part to a circumference of the sample part. In other words, a sample recess, such as the first sample recess and/or the second sample recess, may extend from one cross-sectional edge to another cross- sectional edge. A sample recess, such as the first sample recess and/or the second sample recess, may be straight or curved. A sample recess, such as the first sample recess and/or the second sample recess, may be configured to align with the first fluid path and/or the second fluid path of the microfluidic test device, when the sample plug is inserted into the microfluidic test device.

A sample recess, such as the first sample recess and/or the second sample recess, may have a depth, such as a maximum depth and/or a mean depth larger than 0.5 mm, such as larger than 1 mm, e.g. in the range from 1 mm to 8 mm.

A sample recess, such as the first sample recess and/or the second sample recess, may have a width, such as a maximum width and/or a mean width, in the range from 0.5 mm to 2 mm.

The sample plug/sample recess(es) is/are configured in dimension/material property to hold a sample with a sample volume. The sample volume may be in the range from 1 μΙ_ to 50 μΙ_, such as from 2 μΙ_ to 25 μΙ_.

In one or more exemplary sample plugs having a first sample recess and a second sample recess, the first sample recess may cross the second sample recess and/or the first sample recess and the second sample recess may coincide. In one or more exemplary sample plugs, the first sample recess and the second sample recess are separate, e.g. parallel.

The sample part may comprise a hydrophilic surface. For example, the first sample recess and the second sample recess may be hydrophilic, e.g. by a hydrophilic coating.

The sample plug or parts thereof, e.g. the sample part, may be made of a plastic and/or polymer material. The sample plug optionally comprises a sealing part with a sealing surface for forming a seal with a sample inlet of the microfiuidic test device when the sample plug is inserted into the microfiuidic test device, e.g. into a body of the microfiuidic test device. Thus, the sample plug when inserted in the microfiuidic test device may form a closed test environment (chambers and fluid paths). A seal between the sample plug and the sample inlet may provide (improved) control of fluid flow (liquid and/or gas) through the microfiuidic test device.

The sealing part may comprise a conical or frustum-shaped first outer surface of the sample plug. The conical or frustum-shaped first outer surface of the sample plug may be configured to contact a corresponding conical or frustum-shaped sealing surface of the sample inlet. The sealing part may have a varying diameter along the axis. The sealing part may have a maximum diameter (maximum extension perpendicular to the axis) in the range from 2 mm to 20 mm. In one or more exemplary sample plugs, the sealing surface of the sealing part comprises a frustum of a right cone.

The sealing part may be configured to provide a press-fit arrangement with the sample inlet (sealing surface of the sample inlet).

The sealing surface of the sealing part optionally has a circular first cross section perpendicular to the axis. In one or more exemplary sample plugs, the sealing part has a non-circular, such as oval, cross-section perpendicular to the axis. A sealing part with circular cross-section may facilitate a tight seal with the sample inlet. The sealing part of the sample plug may have a length (extension along the axis) in the range from 1 mm to 20 mm, such as from 2 mm to 10 mm.

The sealing surface optionally has a first sealing surface normal forming a first angle with the axis, wherein the first angle is in the range from 85° to 90°, such as 86°, 87°, 88°, or 89°. A slightly tapering sealing surface with reduced diameter towards the first end of the sample plug enables a sealing press-fit between the sample plug and the body of the microfiuidic test device.

The sample plug may comprise a guide member for guiding the sample plug when inserted and/or during insertion into the microfiuidic test device (sample inlet of the microfiuidic test device). The guide member optionally comprises a flange radially protruding from the axis, the flange comprising one or more guide cuts for

engagement with one or more guide elements of the microfiuidic test device. In one or more exemplary sample plugs, the one or more guide cuts comprises a first guide cut and/or a second guide cut. Provision of a guide member assists the user during insertion of the sample plug into the microfiuidic test device, e.g. by centering the first end in the sample inlet. Thus, the risk of the first end touching the housing or other parts of the microfluidic test device during insertion (which may lead to loss of sample) is reduced. The flange may be non-circular, i.e. the flange may have a non- circular cross-section. A non-circular flange (or guide member in general) may together with one or more guide elements of the microfluidic test device prevent rotation of the sample plug either during and/or after insertion of the sample plug into the microfluidic test device.

In one or more exemplary sample plugs, the sealing part is arranged between the first end and the guide member. Thereby a seal close to the first end is provided for, in turn allowing for a thin microfluidic test device.

The sample plug may be a two-part sample plug with a first part optionally

implementing the sample part, and a second part optionally implementing the handle part. The first part and the second part may be assembled in a connection, such as a press-fit, bajonet clutch, glued or welded connection. The first part optionally implements the sealing part and/or the guide member of the sample plug.

A two-part sample plug allows for a more cost efficient microfluidic test system by allowing the second part to be made of cheaper material using less precise moulding tools, while the more expensive sample part needs to be made from a more precise moulding process (more expensive material and/or tools). Further, a two-part sample plug increases the design freedom allowing the second part (handle) to be used for several different microfluidic test systems.

The microfluidic test device may comprise a housing, wherein the body, e.g. with foils, is accommodated within the housing. The housing may have one or more openings to allow access to the inside of the housing, e.g. to the sample inlet. One or more button members may be included in the housing. A first button of the housing may be associated with the first chamber and/or a second button of the housing may be associated with the flow driving device.

The microfluidic test device comprises a body. The body may be an elongated body having a first end and a second end. The body may have a first end surface and/or a second end surface. The body may have one or more first surfaces, e.g. a first primary surface and/or a first secondary surface, and one or more second surface(s). The first surface(s) may be intended for facing upwards when the microfluidic test device is positioned in a test position. The second surface(s) may be intended for facing downwards when the microfluidic test device is positioned in a test position. The body may comprise one or more grooves or recesses, also denoted first groove(s), in the first surface(s). The body may comprise one or more grooves or recesses, also denoted second groove(s), in the second surface(s). The first and/or second grooves may form at least a part of the fluid paths of the microfluidic test device. The body may have one or more through-going bores from first surface(s) to second surface(s). The body one or more through-going bores may form at least a part of the fluid paths of the microfluidic test device.

The body may be made of a body material. The body material may be glass, silicon or a polymer, such as PolyDimethylSiloxane (PDMS). In one or more exemplary microfluidic test devices, the body is made of polypropylene (PP). The body material may be black or grey. A black or grey PP body material is cheap and has good laser welding properties, in turn reducing welding time.

The microfluidic test device may comprise one or more first foils, such as a first primary foil and/or a first secondary foil, attached to the first surface(s) of the body. The microfluidic test device may comprise one or more second foils, such as a second primary foil and/or a second secondary foil, on the second surface(s) of the body.

The first foil(s) and/or the second foil(s) may be attached to the body by laser welding. The first foil(s) may have a thickness in the range from 0.05 mm to 2 mm, such as from 0.2 mm to 0.8 mm. The second foil(s) may have a thickness in the range from 0.05 mm to 2 mm, such as from 0.2 mm to 1.0 mm.

A foil, such as one or more first foils and/or one or more second foil(s) may be made of a flexible material.

The microfluidic test device may comprise a first primary foil attached to the first primary surface of the body. The first primary foil may be made of a first primary foil material. The first primary foil material may be the same as the body material, e.g. to facilitate attachment of the first primary foil to the body. The first primary foil material may be a polymer, such as PolyDimethylSiloxane (PDMS). In one or more exemplary microfluidic test devices, the first primary foil is made of polypropylene (PP). The first primary foil material may be transparent. A transparent first primary foil material allows a user to inspect or follow liquid flow in fluid paths partly formed by the first primary foil. Further, a user is able to read test results through a transparent first primary foil material covering and/or sealing one or more openings in the body.

The microfluidic test device may comprise a first secondary foil attached to the first secondary surface of the body. The first secondary foil may be made of a first secondary foil material. The first secondary foil material may be metal material or an alloy. In one or more exemplary microfluidic test devices, the first secondary foil is made of aluminium.

The microfluidic test device may comprise a second primary foil attached to the second surface of the body. The second primary foil may be made of a second primary foil material. The second primary foil material may be the same as the body material, e.g. to facilitate attachment of the second primary foil to the body. The second primary foil material may be a polymer, such as PolyDimethylSiloxane (PDMS). In one or more exemplary microfluidic test devices, the second primary foil is made of polypropylene (PP). The second primary foil material may be transparent. A transparent second primary foil material allows a user to inspect or follow liquid flow in fluid paths partly formed by the second primary foil.

The microfluidic test device comprises a first chamber having an outlet and holding a first buffer having a first buffer volume. The outlet of the first chamber may be provided with a first valve. The first valve may be configured to open when the pressure on the inlet side of the first valve is larger than a first pressure threshold. The first chamber may have a first volume in the range from 10 microliters to 900 microliters. In one or more exemplary microfluidic test devices, the first chamber has a first volume in the range from 30 microliters to 1,000 microliters, such as 300 microliters, 400 microliters, 500 microliters, or 600 microliters, 700 microliters, 800 microliters, 900 microliters, or any ranges therebetween.

The first buffer may comprise components useful in amplifying a nucleotide target in the sample. In one embodiment, such amplification is provided by Loop-mediated isothermal amplification (LAMP). In LAMP, the target sequence is amplified at a constant temperature typically 60-65 °C using either two or three sets of primers and a polymerase with high strand displacement activity in addition to a replication activity. Typically, 4 different primers are used to identify 6 distinct regions on the target gene, which adds highly to the specificity. An additional pair of "loop primers" can further accelerate the reaction. Due to the specific nature of the action of these primers, the amount of DNA produced in LAMP is considerably higher than PGR based amplification.

The first buffer optionally comprises a neutral chemical compound with a positively charged cationic functional group such as a quaternary ammonium or phosphonium cation (generally: onium ions) which bears no hydrogen atom and optionally with a negatively charged functional group such as a carboxylate group which may not be adjacent to the cationic site. The neutral chemical compound may be Betaine. The first buffer optionally comprises one or more inorganic salts, such as but not limited to MgS0₄ and/or (NH₄)₂S0₄.

The microfluidic test device comprises one or more reaction chambers including a primary reaction chamber. The primary reaction chamber may have a volume larger than 20 microliters and/or less than 500 microliters. In one or more exemplary microfluidic test devices, the primary reaction chamber may have a volume in the range from 40 microliters to 200 microliters, such as 50 microliters, 75 microliters, 100 microliters, 125 microliters, 150 microliters, 175 microliters, or any ranges therebetween. The microfluidic test device may comprise a primary reaction chamber plug forming a part of the primary reaction chamber. A microfluidic test device with reaction chamber plugs facilitates positioning of reaction material in reaction chamber(s). For example, a pellet with reaction material, such as a primary pellet with primary reaction material may be placed in a primary reaction chamber body part followed by a closing of the primary reaction chamber with a primary reaction chamber plug.

The microfluidic test device may comprise reaction material arranged or deposited at different positions in the microfluidic test device.

The microfluidic test device may comprise a primary reaction material. The primary reaction material may be arranged in the primary reaction chamber.

The primary reaction material optionally comprises short strands of RNA and/or DNA (generally about 18-22 bases) that serve as a starting point for DNA synthesis.

In one or more exemplary microfluidic test devices, the primary reaction material comprises nucleoside triphosphate (NTP).

In one or more exemplary microfluidic test devices, the primary reaction material comprises an enzyme capable of synthesising chains or polymers of nucleic acids, optionally in combination with NTP and/or short strands of RNA and/or DNA. The enzyme capable of synthesising chains or polymers of nucleic acids may be a LAMP polymerase.

The primary reaction material may be subjected to a freeze-drying process to protect the reagents and ensure the stability and re-suspendability properties of the reagent(s) prior to the introduction of the reagent into the primary reaction chamber. Thus, in one or more exemplary microfluidic test devices, the primary reaction material is in a dry and/or pellet like form. The primary reaction material may be coated onto a surface of the body and/or a foil of the microfluidic test device.

The microfluidic test device comprises a sample inlet for receiving a sample. The sample inlet is configured for feeding a sample having a sample volume, into the medical test device.

The sample inlet of the microfluidic test device optionally comprises a sealing surface for forming a seal with the sealing part of the sample plug. The sealing surface of the sample inlet may be formed as a conical or frustum-shaped sealing surface, e.g. in the body, configured to contact a corresponding conical or frustum-shaped sealing surface of the sample plug. A tight seal between the sample inlet and the sample plug is advantageous due to improved flow control of fluid in the microfluidic test device. The sealing surface of the sample inlet is advantageously formed in the sample inlet body part of the body of the microfluidic test device. Further, leakage of fluid during testing is avoided.

The microfluidic test device may comprise one or more guide elements, such as one, two, three, four or more guide elements, for guiding the sample plug when inserted into the microfluidic test device.

The microfluidic test device optionally comprises a first guide element for guiding the sample plug when inserted into the microfluidic test device. The microfluidic test device optionally comprises a second guide element for guiding the sample plug when inserted into the microfluidic test device. A guide element may be configured for engagement with one or more guide cuts of a guide member of the sample plug, e.g. a flange of a guide member. The first guide element and/or the second guide element may be formed as part of the body of the microfluidic test device. A guide element, such as the first guide element and/or the second guide element, may be formed as a rod extending from a first surface of the body, such as the first primary surface or the first secondary surface. The first guide element and the second guide element may be arranged on each side of the sample inlet, i.e. the sample inlet is placed between the first guide element and the second guide element. The guide element(s) may have a height of at least 5 mm, such as at least 10 mm. The guide elements and/or the guide cuts may be arranged such as to reduce or prevent lateral and/or rotational movement of the sample plug during insertion of the sample plug into the microfluidic test device. The sealing surfaces of the sample plug and the sample inlet may also form, fully or part of, a press-fit connection between the sample plug and the microfluidic test device.

In one or more exemplary microfluidic test systems, the first end surface of the sample plug is configured to flush or align with the second surface of the body of the microfluidic test device when inserted into the microfluidic test device. In other words, the first end of the sample plug may contact the second foil of the microfluidic test device after insertion/press-fit of the sample plug and/or the distance between the second foil of the microfluidic test device and the first end of the sample plug may be less than 0.2 mm when the sample plug is inserted into/press-fitted with the (body of the) microfluidic test device. Thereby, a good flushing of sample recess(es) of the sample plug is provided.

The microfluidic test device comprises a first fluid path. The first fluid path may connect the outlet of the first chamber and the sample inlet. The first fluid path may comprise a first branch and a second branch in parallel to the first branch. The first branch of the first fluid path may be connected to a first inlet of sample chamber formed by sample inlet and sample plug. Thus, the first branch may feed first buffer into the sample chamber via first inlet. The second branch of the second fluid path may be connected to a second inlet of sample chamber formed by sample inlet and sample plug. Thus, the second branch of the first fluid path may feed first buffer into the sample chamber via second inlet. A plurality of branches in the first fluid path, the branches connected to respective sample chamber inlets in the microfluidic test device provides improved flushing of the sample. In one or more exemplary microfluidic test devices, the sample chamber only has a single inlet.

The microfluidic test device comprises a second fluid path. The second fluid path may connect the sample inlet and the primary reaction chamber. The second fluid path may comprise a first branch and a second branch in parallel to the first branch. The first branch and the second branch of the second fluid path are optionally connected to respective first outlet and second outlet of the sample chamber. Thus, liquid from the sample chamber may enter the first branch and the second branch of the second fluid path via respective first outlet and second outlet of the sample chamber. The first branch and the second branch of the second fluid path may be joined in second fluid path joint to a single fluid path part, optionally before splitting into second primary fluid path and second secondary fluid path. In one or more exemplary microfluidic test devices, the second primary fluid path is directly connected to first outlet of sample chamber and the second secondary fluid path is directly connected to the second outlet of sample chamber. In one or more exemplary microfluidic test devices, the sample chamber only has a single outlet that may later be branched into second primary fluid path and second secondary fluid path.

The microfluidic test device comprises a primary test part comprising a primary test chamber.

The microfluidic test device comprises a third primary fluid path optionally connecting the primary reaction chamber and the primary test part.

The microfluidic test device may comprise a primary valve arranged in the third primary fluid path. The primary valve acts as a blocking mechanism to separate the primary test part and liquid (sample, first buffer and reaction material) during a reaction time. The primary valve may be configured to open when the pressure on the inlet side of the primary valve is larger than a primary pressure threshold.

The microfluidic test device comprises a flow driving device configured to move fluid (primary test liquid) from the primary reaction chamber to the primary test part. Thus, a user operating the flow driving device may be able to break or force primary valve to open.

The microfluidic test device optionally comprises a heating assembly configured to heat a (primary) reaction fluid in the primary reaction chamber.

The heating assembly may be configured to heat the (primary) reaction fluid in the primary reaction chamber to a primary reaction temperature in the range from 30°C to 100°C, preferably in the range from 30°C to 70°C, such as in the range from 45°C to 68°C. In one or more exemplary microfluidic test devices, the primary reaction temperature is in the range from 55°C to 65°C, such as from 58°C to 63°C. In one or more exemplary microfluidic test devices, the primary reaction temperature is 55°C, 56°C, 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C, 64°C and/or 65°C.

The heating assembly may comprise one or more heating elements, such as one or more primary heating elements, e.g. for heating the primary reaction chamber.

The heating assembly may comprise a primary heating element adjacent the primary reaction chamber.

The primary heating element may be configured to self-regulate to a primary temperature, e.g. upon application of a primary voltage. The primary temperature may be in the range from 30°C to 100°C, preferably in the range from 30°C to 80°C, such as in the range from 45°C to 75°C. In one or more exemplary microfluidic test devices, the primary temperature is in the range from 55°C to 70°C, such as from 58°C to 67°C. In one or more exemplary microfluidic test devices, the primary temperature is 55°C, 56°C, 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C, 64°C and/or 65°C. In one or more exemplary microfluidic test devices, the primary voltage is in the range from 0.5V to 5V, such as in the range from 1.5V to 3.5 V, e.g. 3V A self- regulating primary heating element reduces or eliminates the need for electrical control circuitry, in turn providing a simple temperature control.

The microfluidic test device may comprise a first terminal and a second terminal. The primary heating element may be connected to the first terminal (first side and/or first end of primary heating element) and the second terminal (first side and/or first end of primary heating element) for applying a voltage to the heating assembly, such as the primary heating element.

The heating assembly, e.g. when configured for two-reaction chamber heating, may have a length in the range from 15 mm to 50 mm, such as from 20 mm to 30 mmm e.g. 24 mm. The heating assembly, e.g. when configured for two-reaction chamber heating, may have a width in the range from 5 mm to 30 mm, such as from 10 mm to 20 mmm e.g. 11 mm. The heating assembly may have a thickness in the range from 0.2 mm to 3 mm.

The heating assembly may comprise a first electrode layer arranged on a first side of the primary heating element. The heating assembly may comprise a second electrode layer arranged on a second side of the primary heating element. Thus, the primary heating element may be sandwiched between the first electrode layer and second electrode layer for applying a primary voltage to the primary heating element. The first electrode layer (and thus the primary heating element) and second electrode layer (and thus the primary heating element) may be respectively connected to first terminal and second terminal. The first terminal and the second terminal may be arranged in a battery docket of the microfluidic test device. Accordingly, the microfluidic test device may comprise a battery docket for accommodating one or more batteries. The first terminal and the second terminal may be arranged in a connector for connecting an external power source to the microfluidic test device. The first electrode layer and/or the second electrode layer may be made of a suitable electrode material, such as copper, nickel or an alloy comprising copper and/or nickel.

The heating assembly, e.g. first electrode layer of the heating assembly, may be attached to the second primary foil, e.g. by gluing. The heating assembly may be adjacent to and/or overlapping the primary and secondary reaction chambers. The primary heating element may comprise a resin material and/or one or more polymers. The primary heating element may comprise a carbon-based heater resin. The primary heating element may be made of a material with positive temperature coefficient of resistance.

In one or more exemplary microfluidic test devices, the microfluidic test device comprises a secondary reaction chamber. The secondary reaction chamber may have a volume larger than 20 microliters and/or less than 500 microliters. In one or more exemplary microfluidic test devices, the secondary reaction chamber may have a volume in the range from 40 microliters to 200 microliters, such as 50 microliters, 75 microliters, 100 microliters, 125 microliters, 150 microliters, 175 microliters, or any ranges therebetween. The microfluidic test device may comprise a secondary reaction chamber plug forming a part of the secondary reaction chamber.

The second fluid path may connect the sample inlet and the secondary reaction chamber. For example, the second fluid path may be Y-shaped with a first end connected to the sample inlet, a primary second end connected to the primary test part, and a secondary second end connected to the secondary reaction chamber.

The microfluidic test device may comprise a secondary test part comprising a secondary test chamber.

The microfluidic test device may comprise a third secondary fluid path connecting the secondary test part and one or more reaction chambers, such as the primary reaction chamber and/or the secondary reaction chamber. The microfluidic test device may comprise a secondary valve arranged in the third secondary fluid path. The flow driving device may be configured to move fluid from the primary reaction chamber to the secondary test part. The flow driving device may be configured to move fluid from the secondary reaction chamber to the secondary test part.

The secondary valve acts as a blocking mechanism to separate the secondary test part and liquid (sample, first buffer and reaction material) during a reaction time. The secondary valve may be configured to open when the pressure on the inlet side of the secondary valve is larger than a secondary pressure threshold. Thus, a user operating the flow driving device may be able to break or force secondary valve to open.

The microfluidic test device may comprise a secondary reaction material. The secondary reaction material may be arranged in the secondary reaction chamber. The secondary reaction material may be the same as or different from the first reaction material. The secondary reaction material optionally comprises short strands of RNA and/or DNA (generally about 18-22 bases) that serve as a starting point for DNA synthesis.

In one or more exemplary microfluidic test devices, the secondary reaction material comprises nucleoside triphosphate (NTP).

In one or more exemplary microfluidic test devices, the secondary reaction material comprises an enzyme capable of synthesising chains or polymers of nucleic acids, optionally in combination with NTP and/or short strands of RNA and/or DNA. The enzyme capable of synthesising chains or polymers of nucleic acids may be a LAMP polymerase.

The secondary reaction material may be subjected to a freeze-drying process to protect the reagents and ensure the stability and re-suspendability properties of the reagent(s) prior to the introduction of the reagent into the secondary reaction chamber. Thus, in one or more exemplary microfluidic test devices, the secondary reaction material is in a dry and/or pellet like form.

The heating assembly may be configured to heat a (secondary) reaction fluid in the secondary reaction chamber to a secondary reaction temperature in the range from 30°C to 100°C, preferably in the range from 30°C to 70°C, such as in the range from 45°C to 68°C. In one or more exemplary microfluidic test devices, the secondary reaction temperature is in the range from 55°C to 65°C, such as from 58°C to 63°C. In one or more exemplary microfluidic test devices, the secondary reaction

temperature is 55°C, 56°C, 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C, 64°C and/or 65°C.

The first primary heating element may be configured to heat the secondary reaction chamber. The heating assembly may comprise one or more heating elements, such as one or more secondary heating elements, e.g. for heating the secondary reaction chamber. The heating assembly may comprise a secondary heating element adjacent the secondary reaction chamber. The primary heating element may be adjacent the secondary reaction chamber.

The secondary heating element may be configured to self-regulate to a secondary temperature, e.g. upon application of a secondary voltage. The secondary

temperature may be the same as or different from the primary temperature. The secondary temperature may be in the range from 30°C to 100°C, preferably in the range from 30°C to 80°C, such as in the range from 45°C to 75°C. In one or more exemplary microfluidic test devices, the primary temperature is in the range from 55°C to 70°C, such as from 58°C to 67°C. In one or more exemplary microfluidic test devices, the primary temperature is 55°C, 56°C, 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C, 64°C and/or 65°C. In one or more exemplary microfluidic test devices, the secondary voltage is the same as or different from the primary voltage. The secondary voltage may be in the range from 0.5V to 5V, such as in the range from 1.5V to 3.5 V, such as 3V. A self-regulating primary heating element reduces or eliminates the need for electrical control circuitry, in turn providing a simple temperature control. Thus, the microfluidic test device enables different tests with different test temperatures in the same microfluidic test device. Primary and/ secondary voltages less than 5V may be advantageous for a POCT device, e.g. for a battery-driven POCT device.

The flow driving device may comprise a second chamber having an outlet optionally provided with a second valve, wherein the outlet of the second chamber is connected to the first fluid path or the second fluid path. The second valve may be configured to open when the pressure on the inlet side of the second valve is larger than a second pressure threshold. Thus, the microfluidic test device may comprise a fourth fluid path connecting the outlet of the second chamber and the first fluid path or the second fluid path. In one or more exemplary microfluidic test devices, the second chamber has a second volume in the range from 30 microliters to 2,000 microliters, such as 300 microliters, 400 microliters, 500 microliters, 600 microliters, 800 microliters, 1,000 microliters, 1,20 microliters, 1,400 microliters, 1,600 microliters, 1,800 microliters, or any ranges therebetween. The microfluidic test device may comprise a second fluid, such as air and/or liquid in the second chamber.

The microfluidic test system may comprise a seal covering the sample inlet. The seal may be peeled off, removed or broken prior to or just prior to testing by inserting a sample plug into the microfluidic test device. Thus, the risk of contaminating the inside of the microfluidic test device may be reduced.

A test part of the microfluidic test device, such as the primary test part and/or the secondary test part may comprise a second lateral flow strip. Thus, the primary test part may comprise a first lateral flow strip having a first end connected to or inserted into an outlet of the primary test chamber. The secondary test part may comprise a second lateral flow strip having a first end connected to or inserted into an outlet of the secondary test chamber. A plurality of lateral flow strips enables detection of faulty tests and/or enables performance of different tests on a single sample. The first lateral flow strip may have a length in the range from 30 mm to 100 mm, such as in the range from 40 to 80 mm. In one or more exemplary microfluidic test devices, the first lateral flow strip has a length in the range from 60 mm to 70 mm.

The first lateral flow strip may have a width in the range from 1 mm to 10 mm, such as in the range from 1.5 mm to 4.0 mm. Narrow lateral flow strips have reduced requirements for liquid volume. In one or more exemplary microfluidic test devices, the first lateral flow strip has a width in the range from 2.0 mm to 3.5 mm, such as 3.0 mm.

The second lateral flow strip may have a length in the range from 30 mm to 100 mm, such as in the range from 40 to 80 mm. In one or more exemplary microfluidic test devices, the second lateral flow strip has a length in the range from 60 mm to 70 mm.

The second lateral flow strip may have a width in the range from 1 mm to 10 mm, such as in the range from 1.5 mm to 4.0 mm. Narrow lateral flow strips have reduced requirements for liquid volume. In one or more exemplary microfluidic test devices, the second lateral flow strip has a width in the range from 2.0 mm to 3.5 mm, such as 3.0 mm.

Lateral flow strips in the present context are simple devices intended to detect the presence (or absence) of a target analyte in sample (matrix) without the need for specialized and costly equipment.

Typically, these tests are used for medical diagnostics either for home testing, point of care testing, or laboratory use. A widely spread and well known application is the home pregnancy test.

The technology is based on a series of capillary beds, such as pieces of porous paper or sintered polymer. Each of these elements has the capacity to transport fluid (e.g., urine) spontaneously. The first element (the sample pad) acts as a sponge and holds an excess of sample fluid. Once soaked, the fluid migrates to the second element (conjugate pad) in which the manufacturer has stored the so-called conjugate, a dried format of bio-active particles in a salt-sugar matrix that contains everything to guarantee an optimized chemical reaction between the target molecule and its chemical partner that has been immobilized on the particle's surface.

While the sample fluid dissolves the salt-sugar matrix, it also dissolves the particles and in one combined transport action the sample and conjugate mix while flowing through the porous structure. In this way, the analyte binds to the particles while migrating further through the third capillary bed. This material has one or more areas (often called stripes) where a third molecule has been immobilized by the manufacturer. By the time the sample- conjugate mix reaches these strips, analyte has been bound on the particle and the third 'capture' molecule binds the complex. After a while, when more and more fluid has passed the stripes, particles accumulate and the stripe-area typically changes color.

Lateral flow strip based signal visualization and enhancement is very beneficial on cost perspective, this is presumably the cheapest solution to form simple optical readout that is applicable for point-of-care devices.

While using lateral flow strips for amplicon detection and signal visualization one should also bear in mind that upstream components, including those that are coming from sample matrix, will not inhibit the very binding reaction on lateral flow. This also usually requires balancing of lateral flow buffer and amount of e.g. conjugated gold nanoparticles that are required. Wrong balancing of components will result in signal loss or in nonspecific signals.

Different haptens can be used for the labeling of the primers, including FAM, biotin, DIG, in order to detect amplification product with lateral flow strips. Using different hapten combination multiple product detection can be achieved (multiplex reaction detecting several different pathogens at once).

The body may comprise a first valve body part forming a part of the first valve. The first valve body part may be formed as a recess in a surface of the body, such as a first primary surface, a first secondary surface or a second surface of the body.

The body may comprise a second valve body part forming a part of the second valve. The second valve body part may be formed as a recess in a surface of the body, such as a first primary surface, a first secondary surface or a second surface of the body.

The body may comprise a primary valve body part forming a part of the primary valve. The primary valve body part may be formed as a recess in a surface of the body, such as a first primary surface, a first secondary surface or a second surface of the body.

The body may comprise a secondary valve body part forming a part of the secondary valve. The secondary valve body part may be formed as a recess in a surface of the body, such as a first primary surface, a first secondary surface or a second surface of the body. The body may comprise a primary test chamber body part forming a part of the primary test chamber. The primary test chamber body part may be formed as a recess in a surface of the body, such as a first primary surface, a first secondary surface or a second surface of the body.

The body may comprise a secondary test chamber body part forming a part of the secondary test chamber. The secondary test chamber body part may be formed as a recess in a recess in a surface of the body, such as a first primary surface, a first secondary surface or a second surface of the body.

The body/microfluidic test device may comprise a first flow strip chamber and/or a second flow strip chamber. The first flow strip chamber may be accessible, e.g. for reading test results, through a first opening in a surface of the body, such as a first primary surface, a first secondary surface or a second surface of the body. The second flow strip chamber may be accessible, e.g. for reading test results, through a second opening 70 in a surface of the body, such as a first primary surface, a first secondary surface or a second surface of the body.

The body may comprise one or more holding elements for holding and/or fixate lateral flow strip(s) in position, e.g. between the body and a second foil, such as a second primary foil. The body may comprise one or more first holding elements, such as a first primary holding element and/or a first secondary holding element, in the first flow strip chamber, optionally configured to hold or fixate a first lateral flow strip in position between the body and the second primary foil. The body may comprise one or more second holding elements, such as a second primary holding element and/or a second secondary holding element, in the second flow strip chamber, optionally configured to hold or fixate a second lateral flow strip in position between the body and the second primary foil.

The first primary foil may comprise a primary valve foil part forming a part of the primary valve. The first primary foil may comprise a secondary valve foil part forming a part of the secondary valve. The first primary foil may comprise a first primary test chamber foil part forming a part (top) of the primary test chamber. The first primary foil may comprise a first secondary test chamber foil part forming a part (top) of the secondary test chamber. The first primary foil may cover and/or seal the first opening in the body. The first primary foil may cover and/or seal the second opening in the body. The first secondary foil may comprise a first chamber foil part forming a part of the first chamber. The first secondary foil may comprise a second chamber foil part forming a part of the second chamber.

The first secondary foil may comprise a first valve foil part forming a part of the first valve. The first secondary foil may comprise a second valve foil part forming a part of the second valve.

The first primary foil and the first secondary foil may be made of different materials, e.g. to implement different functions in the microfluidic test device.

The second primary foil may comprise a second primary test chamber foil part forming a part (bottom) of the primary test chamber. The second primary foil may comprise a second secondary test chamber foil part forming a part (bottom) of the secondary test chamber.

The second primary foil may comprise a primary reaction chamber foil part forming a part (bottom) of the primary reaction chamber. The second primary foil may comprise a secondary reaction chamber foil part forming a part (bottom) of the secondary reaction chamber. The heating assembly may be attached to the second primary foil. The heating assembly may partly or fully cover the primary reaction chamber foil part and/or the secondary reaction chamber foil part. Thus, efficient heat transfer to the reaction chambers are provided for.

The second primary foil may comprise a sample inlet foil part forming a part (bottom) of the sample inlet.

The second primary foil may comprise a first flow strip chamber foil part forming a part of the first flow strip chamber and/or a second flow strip chamber foil part forming a part of the second flow strip chamber.

The second primary foil may form a part of one or more fluid paths, such as the first, second, third (primary and secondary), and/or fourth fluid paths.

The method(s) disclosed herein enables complex but yet error-safe and easy-to-use point-of-care testing.

The method comprises sampling a sample with the sample plug. Sampling a sample optionally comprises immersing a sample part of the sample plug in sample liquid, e.g. comprising urine.

Further, inserting the sample plug into a sample inlet of the microfluidic test device may comprise inserting the sample plug in an insertion direction perpendicular to second surface of the body of the microfluidic test device. The axis of the sample plug may be parallel to the insertion direction during insertion.

Inserting the sample plug into a sample inlet of the microfluidic test device may comprise contacting a bottom of the sample inlet, such as a second foil of the microfluidic test device, with the first end of the sample plug. Inserting the sample plug into a sample inlet of the microfluidic test device may comprise aligning first sample recess and/or second sample recess with the first fluid path or at least branches thereof. Inserting the sample plug into a sample inlet of the microfluidic test device may comprise aligning first sample recess and/or second sample recess with the second fluid path or at least branches thereof.

Inserting the sample plug into a sample inlet of the microfluidic test device may be to form a seal between the sample plug and the sample inlet and/or for feeding a sample into the sample inlet. Accordingly, inserting the sample plug into a sample inlet of the microfluidic test device may comprise forming a seal between the sample plug and the sample inlet. Inserting the sample plug into a sample inlet of the microfluidic test device may comprise guiding the sample plug with one or more guide elements of the microfluidic test device. Inserting the sample plug into a sample inlet of the microfluidic test device may comprise press-fitting the sample plug in the body of the microfluidic test device.

The method comprises flushing the sample plug, e.g. first sample recess and/or second sample recess of the sample plug, with first buffer stored in a first chamber of the microfluidic test device. Flushing the sample plug may comprise moving first buffer in a first fluid path towards the sample inlet and moving first buffer and sample in a second fluid path away from the sample inlet.

Turning now to the figures, Fig. 1 schematically illustrates a first (top) view of an exemplary microfluidic test device. The microfluidic test device 2 comprises a body 4 and a first chamber 6 having an outlet 8 provided with a first valve 10 and holding a first buffer having a first buffer volume.

The microfluidic test device 2 comprises a primary reaction chamber 12 and a sample inlet 14 for receiving a sample and being configured for feeding a sample having a sample volume, into the medical test device 2. A first fluid path 16 connects the outlet 8 of the first chamber 6 and the sample inlet 14 and a second fluid path 18 connects the sample inlet 14 and the primary reaction chamber 12. Further, the microfluidic test device 2 comprises a primary test part 20 comprising a primary test chamber 22 with a third primary fluid path 24 connecting the primary reaction chamber 12 and the primary test part 20. A primary valve 26 is arranged in the third primary fluid path 24. The microfluidic test device 2 comprises a flow driving device 28 configured to move fluid from the primary reaction chamber 12 to the primary test part 20. The flow driving device 28 comprises a second chamber 28A having an outlet optionally provided with a second valve 28B. The outlet of the second chamber is connected to the first fluid path 16 via fourth fluid path 29.

The microfluidic test device 2 comprises a heating assembly 30 configured to heat a reaction liquid in the primary reaction chamber 12. The heating assembly 30 is connected to a power source (not shown). The power source may be one or more batteries accommodated or inserted in the microfluidic test device. The power source may be an external power source connected to the microfluidic test device via a connector (not shown).

The primary test part 20 comprises a first lateral flow strip 32 having a first end 34 connected to an outlet of the primary test chamber 22. The first lateral flow strip 32 has a length of 65 mm and a width of 3.0 mm.

Fig. 2 shows an exemplary cross-sectional view of the microfluidic test device 2. The microfluidic test device 2. The body 4 has a first end 36 with a first end surface, and a second end 38 with a second end surface. The body 4 has a first surface 40 intended for facing upwards when the microfluidic test device is positioned in a test position, and a second surface 42 opposite the first surface 40 and intended for facing downwards when the microfluidic test device is positioned in a test position.

The microfluidic test device comprises a first primary foil 44 attached to the first surface 40 of the body 4. The first primary foil 44 forms a part of the third primary fluid path 24 and the primary valve 26.

The microfluidic test device comprises a first secondary foil 46 attached to the first surface 40 of the body 4. The first secondary foil 46 forms a part of the first chamber 6 and the first valve 10.

The microfluidic test device comprises a first tertiary foil 47 attached to the first surface 40 of the body 4. The first tertiary foil 47 forms a part of the flow driving device 28. The flow driving device 28 is embodied as a second chamber with an outlet and a second valve arranged at the outlet of the second chamber.

The microfluidic test device comprises a second primary foil 48 attached to the second surface 42 of the body 4. The first fluid path 16 connects the first chamber 6 and the bottom of sample inlet 14. The second fluid path 18 connects the sample inlet 14 and the first reaction chamber 12. Thus, first buffer can be moved from the first chamber 6 through the first fluid path 16 into the sample inlet 14 by pressing on the first secondary foil 46 with a force sufficient to open the first valve 10, i.e. a force to apply a first pressure larger than the first pressure threshold. The first buffer thus flushes sample in the sample inlet 14 through the second fluid path 18 and into the first reaction chamber 12, where the first buffer, the sample and a primary reaction material are mixed. After a reaction, assisted by heating with heating assembly 30, has taken place, the flow driving device 28 is activated by pressing on the first tertiary foil 47 with a force sufficient to open the second valve 28B, i.e. a force to apply a second pressure larger than the second pressure threshold. Thereby, primary reaction liquid in the primary reaction chamber 12 is moved into the primary test chamber 22 via the third primary fluid path 24 by the primary valve 26 opening upon activation of the flow driving device 28. The primary test liquid in the primary test chamber 22 flows into the first lateral flow strip 32 for obtaining a readout of the test result.

Fig. 3 schematically illustrates a first (top) view of an exemplary microfluidic test device. The microfluidic test device 2A comprises a body 4 and a first chamber 6 having an outlet 8 provided with a first valve 10 and holding a first buffer having a first buffer volume.

The microfluidic test device 2 comprises a primary reaction chamber 12 and a sample inlet 14 for receiving a sample and being configured for feeding a sample having a sample volume, into the medical test device 2. A first fluid path 16 connects the outlet 8 of the first chamber 6 and the sample inlet 14 and a second fluid path 18 connects the sample inlet 14 and the primary reaction chamber 12. Further, the microfluidic test device 2 comprises a primary test part 20 comprising a primary test chamber 22 with a third primary fluid path 24 connecting the primary reaction chamber 12 and the primary test part 20. A primary valve 26 is arranged in the third primary fluid path 24. The microfluidic test device 2 comprises a flow driving device 28 configured to move fluid from the primary reaction chamber 12 to the primary test part 20, and a heating assembly 30 configured to heat a reaction fluid in the primary reaction chamber 12.

The primary test part 20 comprises a first lateral flow strip 32 having a first end 34 connected to an outlet of the primary test chamber 22.

Further, the microfluidic test device 2A comprises a secondary reaction chamber 50, wherein the second fluid path 18 connects the sample inlet 14 and the secondary reaction chamber 50. Further, the microfluidic test device 2A comprises a secondary test part 52 comprising a secondary test chamber 54 with a third secondary fluid path 56 connecting the secondary reaction chamber 50 and the secondary test part 52. A secondary valve 58 is arranged in the third secondary fluid path 56. The flow driving device 28 is configured to move fluid from the secondary reaction chamber 50 to the secondary test part 52, and the heating assembly 30 is optionally configured to heat a reaction fluid in the secondary reaction chamber 50. The secondary test part 52 comprises a second lateral flow strip 60 having a first end 62 connected to an outlet of the secondary test chamber 54. The second lateral flow strip 60 has a length of 65 mm and a width of 3.0 mm.

Figs. 4-10 show different views of exemplary microfluidic test system(s) and parts thereof. The microfluidic test system comprises a microfluidic test device (housing not shown) and a sample plug.

Figs. 4 and 5 show perspective views of parts of microfluidic test device 2B with first part 100A or 100B of a sample plug inserted in the sample inlet of the microfluidic test device. The microfluidic test device 2B comprises a body 4A, 4B and one or more foils attached to surfaces of the body. The microfluidic test device 2B comprises a first primary foil 44 attached to a first primary surface 40A of the body 4A, 4B and forming a part of the third fluid paths (primary and secondary), the primary valve, and the secondary valve of the microfluidic test device 2B. The first primary foil 44 optionally is a flexible plastic foil made of polypropylene that has been laser-welded to the body 4A made of polyproylene. The microfluidic test device 2B comprises a first secondary foil 46 attached to a first secondary surface 40B (See Fig. 6) of the body 4A and forming a part of the first chamber 6, first valve 10, second chamber 28A, and second valve 28B. The first secondary foil 46 optionally is a metal foil, such as an aluminium foil, and/or comprises one or more metal layers.

The first surfaces 40A, 40B are intended for facing upwards when the microfluidic test device 2B is positioned in a test position, and the second surface 42 is intended for facing downwards when the microfluidic test device 2B is positioned in a test position. The microfluidic test device 2B comprises a second primary foil 48 attached to the second surface 42 (See Fig. 7) of the body 4A. Further, the microfluidic test device 2B comprises a heating assembly 30 comprising a primary heating element. The heating element is arranged on the second primary foil 48 adjacent the primary reaction chamber and the secondary reaction chamber and configured to heat the primary reaction chamber (and primary reaction liquid) and the secondary reaction chamber (and secondary reaction liquid). The second primary foil 48 forms a part of the first, second, third (primary and secondary), and fourth fluid paths, primary reaction chamber, secondary reaction chamber, primary test chamber, secondary test chamber, and sample inlet (sample chamber).

The microfluidic test device 2B comprises a primary reaction chamber 12 and a sample inlet 14 for receiving a sample and being configured for feeding a sample having a sample volume, into the medical test device 2B. The microfluidic test device 2B comprises a primary reaction chamber plug 12A forming a part of the primary reaction chamber 12. The sample inlet 14 is configured for receiving first part 100A, 100B of the sample plug carrying the sample. A first fluid path connects the outlet of the first chamber 6 and the sample inlet 14 and a second fluid path connects the sample inlet 14 and the primary reaction chamber 12. Further, the microfluidic test device 2B comprises a primary test part comprising a primary test chamber and a first lateral flow strip with a third primary fluid path connecting the primary reaction chamber 12 and the primary test part (primary test chamber). A primary valve is arranged in the third primary fluid path. The microfluidic test device 2B comprises a flow driving device 28 configured to move fluid from the primary reaction chamber 12 to the primary test part. The flow driving device 28 comprises a second chamber 28A having an outlet optionally provided with a second valve. The outlet of the second chamber is connected to the first fluid path via fourth fluid path.

Further, the microfluidic test device 2B comprises a secondary reaction chamber 50, wherein the second fluid path connects the sample inlet 14 and the secondary reaction chamber 50. The microfluidic test device 2B comprises a secondary reaction chamber plug 50A forming a part of the secondary reaction chamber 50. Further, the microfluidic test device 2B comprises a secondary test part comprising a secondary test chamber and a second lateral flow strip, with a third secondary fluid path connecting the secondary reaction chamber 50 and the secondary test part

(secondary test chamber). A secondary valve is arranged in the third secondary fluid path. The flow driving device 28 is configured to move fluid from the secondary reaction chamber 50 to the secondary test part.

The body 4A, 4B comprises a first guide element 130 and a second guide element 132, respectively formed as a rod or pole. The guide elements 130, 132 guide the sample part (first part 100A, 100B) by engaging respective first and second guide cuts of a guide member of the first part 100A, 100B. The guide elements guide the sample plug (sample part) to prevent undesired lateral movement of the sample plug during insertion of the sample part of the sample plug into the sample inlet in an insertion direction, e.g. perpendicular to the first and/or second surface of the body. This is important to ensure that no sample is wasted or spilled, e.g. due to the sample part touching the microfluidic test device during insertion. Further, the guide elements guide the sample plug (sample part) to prevent undesired rotational movement of the sample plug during insertion of the sample part of the sample plug into the sample inlet thereby ensuring a correct rotational positioning of the sample part.

Fig. 6 shows a perspective view of a body of the microfluidic test device.

A first valve body part 10A of the body 4A forms a part of the first valve 10. The first valve body part 10A is formed as a recess in the first secondary surface 40B of the body 4A. A first through-going bore 16A from the first secondary surface 40B to the second surface 42 forms a part of the first fluid path 18.

A primary reaction chamber body part 12B forms a part of the primary reaction chamber 12. The primary reaction chamber body part 12B is formed as a through- going bore in the body with the primary reaction chamber plug 12A and the second primary foil 48 forming top and bottom of the primary reaction chamber 12.

A primary test chamber body part 22A of the body 4A forms a part of the primary test chamber 22. The primary test chamber body part 22A is formed as a through-going bore from the first primary surface 40A to the second surface 42. The first primary foil 44 and the second primary foil 48 form top and bottom of the primary test chamber 22.

A primary valve body part 26A of the body 4A forms a part of the primary valve 26. The primary valve body part 26A is formed as a recess in the first primary surface 40A of the body 4A. A primary through-going bore 24A from the first primary surface 40A to the second surface 42 forms a part of the third primary fluid path 24.

A second valve body part 28C of the body 4A forms a part of the second valve 28B. The second valve body part 28C is formed as a recess in the first secondary surface 40B of the body 4A. A fourth through-going bore 29A from the first secondary surface 40B to the second surface 42 forms a part of the fourth fluid path 29.

A secondary reaction chamber body part 50B forms a part of the secondary reaction chamber 50. The secondary reaction chamber body part 50B is formed as a through- going bore in the body with the secondary reaction chamber plug 50A and the second primary foil 48 forming top and bottom of the secondary reaction chamber 50.

A secondary test chamber body part 54A of the body 4A forms a part of the secondary test chamber 54. The secondary test chamber body part 54A is formed as a through- going bore from the first primary surface 40A to the second surface 42. The first primary foil 44 and the second primary foil 48 form top and bottom of the secondary test chamber 54.

A secondary valve body part 58A of the body 4A forms a part of the secondary valve 58. The secondary valve body part 58A is formed as a recess in the first primary surface 40A of the body 4A. A secondary through-going bore 56A from the first primary surface 40A to the second surface 42 forms a part of the third secondary fluid path 56.

The microfluidic test device comprises a first flow strip chamber and a second flow strip chamber partly formed in the body 4A. The first flow strip chamber is accessible through a first opening 68 in the first primary surface 40A, and the second flow strip chamber is accessible through a second opening 70 in the first primary surface 40A. The first and second openings enables optical readout of lateral flow strips.

Fig. 7 shows another perspective view of the body 4A, where a first recess 16B forms a part of the first fluid path 16 between the first chamber 6 and the sample inlet 14 partly formed by sample inlet body part 14A. The second fluid path comprises a second primary fluid path 18A and a second secondary fluid path 18B. The second primary fluid path 18A connects the sample inlet 14 and the primary reaction chamber 12, and the second secondary fluid path 18B connects the sample inlet 14 and the secondary reaction chamber 50. A second primary recess 18C in the second surface 42 forms, together with the second primary foil 48, a part of the second primary fluid path 18A. A second secondary recess 18D in the second surface 42 forms, together with the second primary foil 48, a part of the second secondary fluid path 18B.

A fourth recess 29B in the second surface 42 forms, together with the second primary foil 48, a part of the fourth fluid path 29. The fourth fluid path 29 connects the outlet of the second chamber 28A at second valve 28B and the first fluid path 16.

A third primary recess 24B in the second surface 42 forms, together with the second primary foil 48, a part of the third primary fluid path 24.

A third secondary recess 56B in the second surface 42 forms, together with the second primary foil 48, a part of the third secondary fluid path 56.

A first strip chamber recess 64A forms a part of first flow strip chamber for

accommodating a first lateral flow strip. A second strip chamber recess 66A forms a part of second flow strip chamber 66 for accommodating a second lateral flow strip. The second primary foil 48 forms the bottom of the flow strip chambers 64, 66. A first end of the first lateral flow strip is arranged to overlap with the primary test chamber body part 22A such that test liquid in the primary test chamber 22 is fed to the first lateral flow strip. A first end of the second lateral flow strip is arranged to overlap with the secondary test chamber body part 54A such that test liquid in the secondary test chamber 54 is fed to the second lateral flow strip.

First holding elements 72, 74 are provided in the first flow strip chamber 64 of the body 4A. The first primary holding element 72 and the first secondary holding element 74 are configured to hold or fixate the first lateral flow strip in position between the body 4A and the second primary foil 48. Second holding elements 76, 78 are provided in the second flow strip chamber 66 of the body 4A. The second primary holding element 76 and the second secondary holding element 78 are configured to hold or fixate the second lateral flow strip in position between the body 4A and the second primary foil 48.

Fig. 8 shows a second or bottom view of the body 4A. The first fluid path 16 comprises and is split into a first branch formed by first branch recess 17A and second primary foil 48 and a second branch formed by second branch recess 17B and second primary foil 48. The first branch of the first fluid path feeds first buffer into a first inlet of the sample chamber formed by sample inlet and sample plug. The second branch of the second fluid path feeds first buffer into a second inlet of the sample chamber formed by sample inlet and sample plug. A plurality of sample chamber inlets in the microfluidic test device provides improved flushing and/or mixing of the sample. In one or more exemplary embodiments, the sample chamber only has a single inlet.

The second fluid path 18 comprises a first branch formed by first branch recess 19A and second primary foil 48 and a second branch formed by second branch recess 19B and second primary foil 48. Liquid from the sample chamber enters the first branch and the second branch of the second fluid path via respective first outlet and second outlet of the sample chamber. The first branch and the second branch of the second fluid path are joined in second fluid path joint 80 before splitting into second primary fluid path 18A and second secondary fluid path 18B.

Fig. 9 shows a cut out side view of the microfluidic test device 4A illustrating the heating assembly in further detail. The heating assembly 30 comprises a primary heating element 30A sandwiched between a first electrode layer 90 and a second electrode layer 92 for applying a primary voltage to the primary heating element. The heating assembly 30 (first electrode layer 90) is attached to the second primary foil 48 adjacent to and overlapping the primary and secondary reaction chambers 12, 50. A primary pellet of primary reaction material (not shown) is arranged in the primary reaction chamber, and a secondary pellet 94 of secondary reaction material is arranged in the secondary reaction chamber 50. The thin second primary foil 48 provides a good heat transport to reaction liquid in the reaction chambers 12, 50. Thus, low heat loss from the heating assembly to the reaction chambers and precise control of the reaction liquid temperature is provided.

Fig. 10 shows an exemplary body 4B of a microfluidic test device. The sample chamber/sample inlet 14A has a single inlet from the first fluid path. Further, the sample chamber/sample inlet 14A has a single outlet to the second fluid path. In one or more exemplary microfluidic test devices, a single inlet from the first fluid path may be combined with two or more outlets to the second fluid path. Further, two or more inlets from the first fluid path may be combined with a single outlet to the second fluid path.

Fig. 11-14 shows different views of an exemplary first part of a sample plug. The first part 100A is configured to operate with body 4A of microfluidic test device. The first part 100A (and sample plug) extends along an axis X and has a first end 102 with a first end surface 104 and comprising a sample part 106. The first part 100A comprises a first connector part 108 for connecting the first part 100 to a second part of the sample plug, the second part comprising a handle part of the sample plug. The sample part 106 comprises a first sample recess 110 formed in the first end surface 104.

Further, the sample part 106 optionally comprises a second sample recess 112 formed in the first end surface 104. The first sample recess 110 crosses the second sample recess 112 at an angle of at least 45 degrees. In the illustrated sample part, the first sample recess 110 and the second sample recess 112 are perpendicular, each sample recess extending from and to respective cross-sectional edges to form parts of a fluid path through the sample inlet. In other words, the first sample recess 110 and the second sample recess 114 each has a length corresponding to the cross-sectional diameter of the sample part 106.

The first part 100A of the sample plug comprises a sealing part 114 with a sealing surface 116 for forming a seal with a sample inlet, such as sample inlet 14, of the microfluidic test device when the sample plug is inserted into the microfluidic test device, control of fluid flow (liquid and/or gas) through the microfluidic test device.

The sealing part 114/sealing surface 116 comprises a conical or frustum-shaped first outer surface 118 with circular cross-sections along the axis. The diameter of the sealing part 114 decreases slightly along the axis towards the first end 102 of the sample plug. The sealing surface 116 has a first sealing surface normal forming a first angle with the axis, wherein the first angle is 88°.

Further, the sample plug (first part 100A) comprises a guide member 118 for guiding the sample plug when inserted into the microfluidic test device. The guide member 118 comprises a non-circular flange 120 radially protruding from the axis X, the flange 120 comprising one or more guide cuts including first guide cut 122 and second guide cut 124 for engagement with one or more guide elements of the microfluidic test device. As seen, the sealing part 114 is arranged between the first end 102 and the guide member 118. The first part 100 is made of a plastic material, and the sample part 106 is coated with a hydrophilic coating.

Fig. 15 shows a first end view of an exemplary first part of a sample plug. The first part 100B is configured to operate with body 4B of microfluidic test device. The first part 100B corresponds to the first part 100A except that the sample part only has one sample recess, namely first sample recess 110. When insert into the sample inlet, the first sample recess 110 is aligned with the first fluid path recess and the second fluid path recess of body 4B to ensure that first buffer can flush sample to the reaction chambers via the second fluid path.

Fig. 16 is a cut-away end view of the body 4A with first part 100A inserted into the sample inlet body part. The first end of the sample plug is aligned or flush with the second surface 42 of the body 4A and in contact with or at short distance from the second foil (not shown). The sample recesses 110, 112 of the first part 100A are aligned with branch recesses 17A, 17B, 19A, 19B of the first and second fluid paths to form fluid paths through the sample inlet and to ensure that first buffer can flush sample to the reaction chambers via the second fluid path. The sealing surface 116 of the sample plug forms a seal with corresponding sealing surface 134 of the sample inlet. The guide member 118 engages with guide elements 130, 132 to, during and/or after insertion, ensure correct translational and/or rotational orientation of the sample plug.

Fig. 17 illustrates a flow chart of an exemplary method of operating a microfluidic test system comprising a microfluidic test device, e.g. any of microfluidic test device 2, 2A, 2B, and a sample plug, e.g. a sample plug comprising any of first part 100A, 100B. The method 200 comprises sampling 202 a sample with the sample plug, e.g. with sample part of the sample plug; inserting 204 the sample plug into a sample inlet of the microfluidic test device, e.g. to form a seal between the sample plug and the sample inlet and/or for feeding a sample into the sample inlet; and flushing 206 the sample plug, e.g. a first sample recess and/or a second sample recess of the sample plug, with first buffer stored in a first chamber of the microfluidic test device.

Fig. 18 schematically illustrates a microfluidic test system. The microfluidic test system 1 comprises microfluidic test device 2B and sample plug 250. The microfluidic test device 2B comprises housing 252 accommodating body 4A, 4A (not shown). The sample plug 250 comprises handle part 254 forming a second part with a second connector part attached to first connector part of first part 100A, 100B (not shown). The microfluidic test device 250 has a first button 256 and a second button 258. The first button 256 is configured to, when pressed by a user, move first buffer into the sample inlet by collapsing the first chamber 6. The second button 258 is configured to, when pressed by a user, move reaction liquid in reaction chambers 12, 50 to respective test chambers 22, 54 of microfluidic test device 2B by collapsing the second chamber 28A. The housing 252 has a first window 260 and a second window for visual inspection of first and second lateral flow strips arranged in respective flow strip chambers 64, 66. The housing 252 has a sample inlet opening 264 through which the sample plug 250 is inserted into the microfluidic test device, i.e. through which the sample part with the sample is inserted into the sample inlet.

The use of the terms "first", "second", "third", "fourth", "primary", "secondary", etc. does not imply any particular order, but are included to identify individual elements. Moreover, the use of the terms "first", "second", "third", "fourth", "primary",

"secondary", etc. does not denote any order or importance, but rather these terms are used to distinguish one element from another. Note that the words "first", "second", "third", "fourth", "primary", and "secondary", are used here and elsewhere for labelling purposes only and are not intended to denote any specific spatial or temporal ordering. Furthermore, the labelling of a first element does not imply the presence of a second element and vice versa.

Although particular features have been shown and described, it will be understood that they are not intended to limit the claimed invention, and it will be made obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the claimed invention. The specification and drawings are, accordingly to be regarded in an illustrative rather than restrictive sense. The claimed invention is intended to cover all alternatives, modifications and equivalents. LIST OF REFERENCES

1 microfluidic test system

2, 2A, 2B microfluidic test device

4, 4A, 4B body

6 first chamber

8 outlet

10 first valve

10A first valve body part

12 primary reaction chamber

12A primary reaction chamber plug

12B primary reaction chamber body part

14 sample inlet

16 first fluid path

16A first through-going bore

16B first recess

17A first branch recess of first fluid path

17B second branch recess of first fluid path

18 second fluid path

18A second primary fluid path

18B second secondary fluid path

18C second primary recess

18D second secondary recess

19A first branch recess of second fluid path

19B second branch recess of second fluid path

20 primary test part

22 primary test chamber

22A primary test chamber body part

24 third primary fluid path 24A primary through-going bore

24B third primary recess

26 primary valve

26A primary valve body part

28 flow driving device

28A second chamber

28B second valve

28C second valve body part

29 fourth fluid path

29A fourth through-going bore

29B fourth recess

30 heating assembly

3 OA primary heating element

32 first lateral flow strip

34 first end of first lateral flow strip

36 first end of body

38 second end of body

40 first surface of body

40A first primary surface of body

40B first secondary surface of body

42 second surface of body

44 first primary foil

46 first secondary foil

47 first tertiary foil

48 second primary foil

50 secondary reaction chamber

50A secondary reaction chamber plug

50B secondary reaction chamber body part 52 secondary test part

54 secondary test chamber

54A secondary test chamber body part

56 third secondary fluid path

56A secondary through-going bore

56B third secondary recess

58 secondary valve

58A secondary valve body part

60 second lateral flow strip

62 first end of second lateral flow strip

64 first flow strip chamber

64A first strip chamber recess

66 second flow strip chamber

66A second strip chamber recess

68 first opening

70 second opening

72 first primary holding element

74 first secondary holding element

72 first primary holding element

74 first secondary holding element

76 second primary holding element

78 second secondary holding element

80 second fluid path joint

90 first electrode

92 second electrode

94 secondary pellet of secondary reaction material

100 first part of sample plug

102 first end 104 first end surface

106 sample part

108 first connector part

110 first sample recess

112 second sample recess

114 sealing part

116 sealing surface of sample plug

118 guide member

120 flange

122 first guide cut

124 second guide cut

130 first guide element

132 second guide element

134 sealing surface of sample inlet

200 method of operating a microfluidic test system

202 sampling

204 inserting

206 flushing

250 sample plug

252 housing

254 handle part

256 first button

258 second button

260 first window

262 second window

264 sample inlet opening

X axis of sample plug

Claims

1. Sample plug for a microfluidic test system comprising a microfluidic test device and the sample plug, the sample plug extending along an axis and having a first end with a first end surface and comprising a sample part and a handle part, the sample part comprising a first sample recess and a second sample recess formed in the first end surface for feeding a sample into a sample inlet of the microfluidic test device.

2. Sample plug according to claim 1, wherein the first sample recess extends from a circumference of the sample part to a circumference of the sample part.

3. Sample plug according to any of claims 1-2, wherein the first sample recess has a depth larger than 1 mm.

4. Sample plug according to any of claims 1-3, wherein the first sample recess has a width in the range from 0.5 mm to 2 mm.

5. Sample plug according to any of claims 1-4, wherein the second sample recess has a depth larger than 1 mm.

6. Sample plug according to any of claims 1-5, wherein the second sample recess has a width in the range from 0.5 mm to 2 mm.

7. Sample plug according to any of claims 1-6, wherein the first sample recess crosses the second sample recess.

8. Sample plug according to any of claims 1-7, wherein the sample part comprises a hydrophilic surface.

9. Sample plug according to any of claims 1-8, wherein the sample part is made of a plastic material.

10. Sample plug according to any of claims 1-9, wherein the sample plug comprises a guide member for guiding the sample plug when inserted into the microfiuidic test device.

11. Sample plug according to claim 10, wherein the guide member comprises a flange radially protruding from the axis, the flange comprising one or more guide cuts for engagement with one or more guide elements of the microfiuidic test device.

12. Sample plug according to any of claims 1-11, wherein the sample plug is a two- part sample plug with a first part implementing the sample part and a second part implementing the handle part, and wherein the first part and the second part are assembled in a connection.

13. Microfiuidic test system comprising a microfiuidic test device and a sample plug, the microfiuidic test device comprising a body; a first chamber having an outlet and holding a first buffer having a first buffer volume; a primary reaction chamber; a sample inlet for receiving a sample and being configured for feeding a sample having a sample volume, into the medical test device; a first fluid path connecting the outlet of the first chamber and the sample inlet; and a second fluid path connecting the sample inlet and the primary reaction chamber, wherein the sample plug extends along an axis and having a first end with a first end surface and comprising a sample part and a handle part, the sample part comprising a first sample recess and a second sample recess formed in the first end surface for feeding a sample into the sample inlet of the microfiuidic test device.

14. Microfiuidic test system according to claim 13, wherein the microfiuidic test device comprises a first guide element for guiding the sample plug when inserted into the microfiuidic test device.

15. Microfiuidic test system comprising a microfiuidic test device and a sample plug according to any of claims 1-12, the microfiuidic test device comprising a sample inlet, wherein the sealing surface of the sample plug is configured for forming a seal with the sample inlet of the microfluidic test device when the sample plug is inserted into the microfluidic test device.

16. Method of operating a microfluidic test system comprising a microfluidic test device and a sample plug comprising a first sample recess and a second sample recess formed in a first end surface of the sample plug, the method comprising

- sampling a sample with the sample plug;

- inserting the sample plug into a sample inlet of the microfluidic test device for feeding a sample into the sample inlet; and

- flushing the first sample recess and the second sample recess with first buffer stored in a first chamber of the microfluidic test device.