Device for sample analysis

Abstract

A device for analysing a sample comprising a nucleic acid to be captured and detected using a test strip are described. The device comprises a resilient biasing member disposed in an analysis chamber containing the test strip. The resilient biasing member exerts a force against the test strip sufficient to urge it into the sample chamber when it is in communication with the analysis chamber. This ensures that the test strip is reliably introduced into the sample chamber when it is in communication with the analysis chamber. In one embodiment, the sample chamber comprises guide members for guiding the test strip into the sample chamber. A free end of each guide member is shaped to prevent significant rotation of the test strip, so that the test strip is in correct alignment in the sample chamber for automatic reading of the test result, for example by a camera or optical reader.

Claims

1. A device for analyzing a sample, the device comprising: a sample chamber for receiving the sample having a first opening; an analysis chamber containing a test strip for analyzing the sample, the analysis chamber having a second opening; the sample chamber being moveable relative to the analysis chamber to enable communication between the sample chamber and the analysis chamber when the first opening is disposed in an overlapping relationship with the second opening; a resilient biasing member disposed in the analysis chamber and configured to exert a force against the test strip sufficient to urge the test strip into the sample chamber when the first opening is disposed in an overlapping relationship with the second opening, so that the test strip is automatically and reliably introduced into the sample chamber when the first opening is disposed in an overlapping relationship with the second opening; and a sealing apparatus for sealing the sample chamber and the analysis chamber throughout the communication between the sample chamber and the analysis chamber.

2. A device according to claim 1, wherein the resilient biasing member is disposed between a wall of the analysis chamber and the test strip.

3. A device according to claim 2, wherein the wall of the analysis chamber is an end wall opposite the second opening.

4. A device according to claim 1, wherein the resilient biasing member has a cross sectional shape which corresponds to a cross-sectional shape of the analysis chamber.

5. A device according to claim 1, wherein the resilient biasing member has a cross-sectional shape which is substantially rectangular.

6. A device according to claim 1, wherein the resilient biasing member is a spring.

7. A device according to claim 6, wherein an end of the spring comprises a closed coil that has a smaller diameter than other coils of the spring, and contacts an end of the test strip to ensure that the spring is able to urge the test strip with sufficient force.

8. A device according to claim 1, wherein an internal wall of the analysis chamber comprises a rib extending co-axially with the test strip, which reduces contact area between the wall of the analysis chamber and the test strip.

9. A device according to claim 8, wherein the rib extends for at least a third of the length of the analysis chamber.

10. A device according to claim 1, wherein the sample chamber comprises first and second guide members for guiding the test strip into the sample chamber between the guide members, wherein a free end of each guide member is shaped to prevent significant rotation of the test strip about its direction of movement into the sample chamber when the test strip is disposed between the free ends of the guide members.

11. A device according to claim 10, wherein each guide member comprises a free end which is sufficiently flared to prevent significant rotation of the test strip when the test strip is disposed between the free ends of the guide members.

12. A device for analyzing a sample, the device comprising: a sample chamber for receiving the sample having a first opening; an analysis chamber containing a test strip for analyzing the sample, the analysis chamber having a second opening; the sample chamber being moveable relative to the analysis chamber to enable communication between the sample chamber and the analysis chamber when the first opening is disposed in an overlapping relationship with the second opening to allow the test strip to enter the sample chamber, wherein the sample chamber comprises first and second guide members for guiding movement of the test strip into the sample chamber between the guide members, wherein a free end of each guide member is shaped to prevent significant rotation of the test strip about its direction of movement into the sample chamber when the test strip is disposed between the free ends of the guide members to ensure correct alignment of the test strip in the sample chamber for reading of a result on the test strip.

13. A device according to claim 12, wherein each guide member comprises a free end which is sufficiently flared to prevent significant rotation of the test strip disposed between the free ends of the guide members.

14. A device according to claim 13, wherein the flared free end of each guide member has a width which is greater than half, preferably greater than two thirds, of the width of the test strip.

15. A device according to claim 12, wherein there are no more than two guide members.

16. A device according to claim 14, wherein the guide members are paddle shaped.

17. A device according to claim 12, wherein the guide members prevent rotation of the test strip by more than 50° when the test strip is disposed between the guide members.

18. A device for analyzing a sample, the device comprising: a sample chamber for receiving the sample having a first opening; an analysis chamber containing a test strip for analyzing the sample, the analysis chamber having a second opening; the sample chamber being moveable relative to the analysis chamber to enable communication between the sample chamber and the analysis chamber when the first opening is disposed in an overlapping relationship with the second opening to allow the test strip to enter the sample chamber, wherein an internal wall of the analysis chamber comprises a rib extending co-axially with the test strip, which reduces contact area between the wall of the analysis chamber and the test strip, thereby reducing frictional force acting against movement of the test strip into the sample chamber to ensure reliable entry of the test strip into the sample chamber.

19. A device according to claim 18, wherein the rib extends for at least a third of the length of the analysis chamber.

Description

(1) Embodiments of the invention are now described, by way of example only, with reference to the accompanying drawings in which:

(2) FIG. 1a shows a side view of a device according to an embodiment of the invention, in a configuration in which a test strip is located entirely within an analysis chamber of the device; FIG. 1b shows a side view of the device shown in FIG. 1a, in a configuration in which the test strip has been urged into the sample chamber:

(3) FIG. 2 shows a perspective view of the device shown in FIG. 1a; and

(4) FIG. 3 shows a top view of the analysis chamber of the device shown in FIG. 1.

(5) The device shown in FIGS. 1-3 is the same type of device as described at page 38, line 24—page 39, line 8 of WO 2014/140640, with reference to FIG. 11. This device is suitable for use with an automated system of the type described with reference to FIGS. 1 and 2 of WO 2014/140640 as part of a sample processing protocol. The device of the embodiment described herein differs from the device described with reference to FIG. 11 of WO2014/140640 by incorporation of a helical compression spring in the analysis chamber, and first and second guide members in the sample chamber (the sample chamber is referred to as the processing chamber in the device described in WO 2014/140640). FIGS. 1-3 herein have been simplified to remove the sealing cap for sealing the input port prior to processing of the sample, the sealing cap being configured to engage with the adaptor. The device shown in FIGS. 1-3 herein is described in more detail below.

(6) The device 10 comprises an upper portion 12 and a lower portion 14 which are both formed from a mouldable plastics material. The upper and lower portions are both circular and rotatably engageable with each other. A sample chamber 16 is formed in the lower portion. An input port 18 and an analysis chamber 20 are formed in the upper portion. The sample chamber 16 has an upwardly facing opening through which a sample and reagents (and a test strip) can enter the sample chamber.

(7) The analysis chamber 20 is a tall, thin chamber of substantially rectangular internal cross-section, and contains a test strip 22. The analysis chamber is transparent to allow the test strip to be visually inspected, or to be read by an optical reader. The analysis chamber has a downwardly facing opening through which the test strip can pass. A helical compression spring 24 (shown schematically in the figures) is disposed in the analysis chamber between a closed upper end 26 of the analysis chamber and an upper end 28 of the test strip. As seen in FIGS. 2 and 3, the helical compression spring is substantially rectangular in cross-section (i.e. coils of the helical spring follow a substantially rectangular path), and fits snugly within the closed upper end of the analysis chamber. A closed coil 29 at a lower end of the spring has a smaller diameter than other coils of the spring and contacts the upper end of the test strip approximately half-way along the top of the test strip. This ensures that a reliable contact is made between the lower end of the spring and the upper end of the test strip.

(8) FIG. 1a shows the test strip held in the analysis chamber by the lower portion 14. In this initial position, the helical compression spring 24 is compressed between the closed end 26 of the analysis chamber 20 and the upper end 28 of the test strip 22. As seen in FIGS. 2 and 3 (with the helical spring in its compressed position), an internal side wall 30 of the analysis chamber comprises a rib 32 extending co-axially with the test strip. The rib extends from the closed upper end of the analysis chamber to approximately half-way down the analysis chamber. The rib 32 reduces contact area of the side wall of the analysis chamber with the test strip.

(9) The sample chamber comprises an insert 34 comprising an upper ring 36 and first 38 and second 40 flexible but resilient guide members. Each guide member 38, 40 comprises a protrusion extending inwardly from a side wall of the upper ring 36 towards a closed lower end 42 of the sample chamber. A free end of each protrusion is flared so that each guide member is paddle-shaped. The flared free ends of the guide members are disposed opposite one another and spaced sufficiently far apart to allow a lower end 44 of the test strip to pass between them, but sufficiently close together to prevent significant rotation of the test strip in the sample chamber when disposed between the free ends of the guide members.

(10) Once a sample has been processed, and it is desired to test the sample for presence of a specific amplified nucleic acid, the upper portion is rotated relative to the lower portion to a position in which the opening of the sample chamber is in an overlapping relationship with the opening of the analysis chamber. The test strip is urged by the helical spring into the sample chamber so that a lower end of the test strip is in contact with a processed sample in the sample chamber. In this position, shown in FIG. 1b, the helical spring is extended. The lower end of the helical spring remains in contact with the upper end of the test strip to retain the test strip in position in the sample chamber. The force exerted against the test strip by the helical spring is sufficient to urge the test strip into the sample chamber when the opening of the sample chamber is in an overlapping relationship with the opening of the analysis chamber, but not so strong as to cause deformation of the test strip by the force exerted by the helical spring either in its compressed or extended position. The rib 32 reduces the contact area of the test strip with the side wall of the analysis chamber, thereby reducing the frictional force acting against movement of the test strip into the sample chamber.

(11) As the test strip is urged into the sample chamber by the action of the helical spring, the lower end of the test strip passes between the paddle-shaped guide members in the sample chamber. The guide members guide the test strip into position in the sample chamber, and the flared ends of the guide members ensure that the test strip does not rotate significantly once in position so that it is in correct alignment with an optical reader (not shown) able to read a result on the test strip. The force exerted by the spring ensures that the lower end 44 of the test strip contacts the bottom of the sample chamber so that all of the sample in the sample chamber wicks up the test strip by capillary action. The test strip is sensitive to the presence of a particular nucleic acid and provides a visual indication, such as a line on the test strip, if it contacts a sample containing that nucleic acid.