Test kit for detecting acetylcholinesterase inhibitors

Abstract

A test kit for detecting organophosphate compounds, includes a support apparatus, a sampling device, a buffer solution in a sample tube, and an acetylcholinesterase as the first active component and a mixture of 5,5′-dithiobis(2-nitrobenzoic acid) (DTNB) and acetylthiocholine. The sampling device is packaged in a sample tube, where the first active component is applied in a first reagent cap and the second active component is applied in a second reagent cap, and the first and second reagent caps each seal a sample tube. The support apparatus has at least four fixing devices for receiving the sample tubes. The sample tubes are fixed parallel to the upper side of the support apparatus, and the support apparatus has at least two receiving devices for receiving the first and second reagent caps and one receiving device for vertically receiving a sample tube.

Claims

1. A test kit for detecting organophosphate compounds, comprising: a support apparatus having an upper side and an underside, a sampling device, a buffer solution in a sample tube having a cap, and an acetylcholinesterase as the first active component, and a mixture of 5,5′-dithiobis(2-nitrobenzoic acid) (DTNB) and acetylthiocholine, wherein the sampling device is packaged in a sample tube having a cap, the first active component is applied in a first reagent cap and the second active component is applied in a second reagent cap, and the first and second reagent caps each close a sample tube, wherein the support apparatus has at least four fixing devices for receiving the sample tubes, wherein the fixing devices are formed by recesses in the support apparatus, the sample tubes are fixed parallel to the upper side of the support apparatus, and wherein the support apparatus has at least two receiving devices for receiving the first and the second reagent caps and a receiving device for vertically receiving a sample tube.

2. The test kit according to claim 1, wherein the support apparatus contains plastic, and preferably a plastic, such as acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), polypropylene (PP), polystyrene (PS), polycarbonate (PC), or polyethylene (PE).

3. The test kit according to claim 1, wherein the support apparatus is designed in one piece.

4. The test kit according to claim 1, wherein the fixing devices for receiving the sample tubes are formed as depressions in the upper side of the support apparatus, and the individual fixing devices are arranged in a row on the support apparatus.

5. The test kit according to claim 1, wherein the fixing devices are designed as clamping or plug-in devices.

6. The test kit according to claim 5, wherein the fixing devices are designed as clamping devices, have a circular arc-shaped cross-section, and the arc length of the cross-section is greater than half the circumference of the corresponding circle.

7. The test kit according to claim 5, wherein the support apparatus has recesses on the upper side between the individual clamping devices, and the recesses have an angular, round, or a rectangular, cross-section.

8. The test kit according to claim 1, wherein the receiving devices for receiving the reagent caps are formed as depressions on the upper side of the support apparatus and are designed to be circular, wherein the circular diameter is larger than the diameter of the reagent caps.

9. The test kit according to claim 8, wherein a depth of the depressions is smaller than the height of the reagent caps.

10. The test kit according to claim 1, wherein the device for receiving the test tube is formed as a circular depression on the upper side of the support apparatus.

11. The test kit according to claim 1, wherein the device for receiving the test tube and the devices for receiving the reagent caps are arranged in a row, and/or wherein the support apparatus has a closed underside, and/or wherein buffer solution has a pH range of 6 to 8, and/or wherein the acetylcholinesterase is human acetylcholinesterase.

12. The test kit according to claim 1, wherein the test kit is shrink-wrapped in a film pouch as packaging, and/or at least one label is applied to the packaging.

13. The test kit according to claim 1, wherein the packaged test kit is packaged flat, and/or wherein the sample tubes that are closed with the caps contain a desiccant or a packaged desiccant, and/or wherein the sample tubes have a screw thread, and/or wherein the caps are formed as a screw cap.

14. The test kit according to claim 1, comprising a configuration to detect an acetylcholinesterase inhibitor.

15. The test kit according to claim 14, wherein the acetylcholinesterase inhibitor comprises a nerve agent.

16. The test kit according to claim 15, wherein the nerve agent comprises sarin, tabun, VX, mustard gas, soman, cyclosarin and/or Novichok, a pesticide, or another substance that inhibits acetylcholinesterase.

17. A method for detecting an acetylcholinesterase inhibitor using a test kit according to claim 1, comprising: a) swabbing the surface to be examined using a sampling device; b) placing the sampling device in a sample tube, wherein the sample tube contains a buffer solution; and c) sealing the sample tube with a first reagent cap and shaking the sample tube sealed with the reagent cap, wherein acetylcholinesterase is located in the reagent cap as a first reactive component and, by shaking, any AChE inhibitor present from the sampling device and the acetylcholinesterase contained in the reagent cap are brought into the buffer solution so that a sample solution is formed.

18. The method according to claim 17, further comprising: d) leaving the sample tube in order to binding of the Ache inhibitor possibly contained in the sample solution to the acetylcholinesterase; e) replacing the reagent cap with a second reagent cap, the second reagent cap containing, as a second component, DTNB and acetylthiocholine, and sealing the sample tube with the second reagent cap; f) shaking the sample tube sealed with the second reagent cap to release the second reactive component from the second reagent cap such that a solution is obtained; and g) visually comparing a coloration of the solution with a color chart, wherein if the solution is colorless, the presence of an acetylcholinesterase inhibitor is detected.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The invention is described in more detail below with reference to FIGS. 1 through 11. Shown are:

[0029] FIG. 1 a schematic representation of the detection reaction of acetylcholinesterase inhibitors with the help of the test kit,

[0030] FIG. 2 a schematic representation of the test kit in plan view,

[0031] FIG. 3 a schematic representation of the support apparatus in plan view,

[0032] FIG. 4 a schematic representation of a cross-section through the partial region of a support apparatus having a cap holder and sample holder,

[0033] FIG. 5 a schematic representation of a cross-section through the partial region of a support apparatus having fixing devices,

[0034] FIG. 6 a schematic representation of a cross-section through the partial region of a support apparatus having a cap and sample tube,

[0035] FIG. 7 a photograph of an outer packaging of a test kit as an embodiment,

[0036] FIG. 8 a photograph of a test kit as an exemplary embodiment,

[0037] FIG. 9 a photograph of a test kit, wherein the test kit was prepared for performing the detection reaction,

[0038] FIG. 10 a photograph of a packaged test kit from the prior art, and

[0039] FIG. 11 a photograph of the individual components of the test kit shown in FIG. 10.

DETAILED DESCRIPTION OF THE INVENTION

[0040] FIG. 1 is a schematic representation of the performance of the test for acetylcholinesterase inhibitors—in particular, a nerve agent, such as sarin, tabun, VX, mustard gas, soman, cyclosarin and/or Novichok, a pesticide or another substance that inhibits acetylcholinesterase—with the test kit according to the invention. In a first step a), a swab is taken of the surface 8 to be examined, using the sampling device 6, e.g., a cotton swab, and the sampling device 6 is placed in a sample tube 32 with a buffer solution 7.

[0041] Subsequently, in step b), the reagent cap 42 is screwed onto the sample tube 32. Acetylcholinesterase is located in the reagent cap 42 as the first reactive component.

[0042] The sample tube 32 is then shaken for 10 seconds, and thus both the AChE inhibitor possibly absorbed by the sampling device and the acetylcholinesterase present in the cap 42 are brought into the buffer solution such that the sample solution 10 is formed.

[0043] After a waiting time of one minute, within which the AChE inhibitor optionally present can bind to AChE and thus completely or partially inhibit it, in step c), the reagent cap 42 is replaced by the reagent cap 43. DTNB and acetylthiocholine are located in the reagent cap 43 as the second reactive component. In order to dissolve the second reactive component out of the reagent cap 43, the sample tube 32 is shaken again, so that the sample solution 10 can dissolve the components out of the reagent cap 43.

[0044] Subsequently, the coloring of the solution 11 thus obtained is compared with a color chart. A yellow coloration of the solution 11 is caused by the TNB2− ion and indicates the presence of an active, i.e., non-inhibited, acetylcholinesterase in solution 11. A yellow coloration is therefore an indicator of the absence of an acetylcholinesterase inhibitor in sample 8, and thus represents a negative result for acetylcholinesterase inhibitors. If, on the other hand, the sample 8 contains acetylcholinesterase inhibitors, a yellow coloration of the solution 11 remains in step c), or only a very weak yellow coloration of the solution 11 can be observed.

[0045] FIG. 2 is a schematic representation of the test kit 1 in plan view. The test kit 1 comprises the support apparatus 2, as well as the sample tubes 30, 32, 33, 34 having the caps 40, 41 and the reagent covers 42, 43. The sample tubes 30, 32, 33, 34 are fixed in the fixing devices 20, 21, 22, 23. The fixing devices 20, 21, 22, 23 represent recesses on the upper side 18 (FIG. 5) of the support apparatus 2 and are arranged parallel to one another in a row. In the embodiment shown in FIG. 2, the fixing devices 20, 21, 22, 23 are designed as clamping devices. In order to ensure the flexibility of the fixing devices 20, 21, 22, 23 that is necessary for clamping the sample tubes 30, 32, 33, 34, the support apparatus 2, between the fixing devices 20, 21, 22, 23, has recesses 204, 205, 206 on the upper side 18 of the support apparatus 2.

[0046] The sample tubes 30, 32, 33, 34 are fixed parallel to one another and horizontally with respect to the upper side 18 of the support apparatus by means of the fixing devices 20, 21, 22, 23. In this case, the sample tubes 30, 32, 33, 34 are only partially fixed in the fixing devices 20, 21, 22, 23. While the lower part of the sample tubes 30, 32, 33, 34 is located within the fixing devices, the upper part of the sample tubes 30, 32, 33, 34 having the caps 40, 41 and the reagent caps 42, 43 is freely accessible such that removal of the sample tube is not absolutely necessary for removing the caps 40, 42, 43. The arrangement of the individual sample tubes 30, 32, 33, 34 shown in the embodiment leads to a small overall size of the test kit.

[0047] The support apparatus 2 also has the two cap holders 201, 202 and the sample holder 203, which are formed as depressions on the upper side 18 of the support apparatus 2. In the embodiment shown in FIG. 2, cap holders 201, 202 and sample holder 203 are arranged in a row above the fixing devices 20, 21, 22, 23.

[0048] Sample tubes 30 contain the sample receiving device 6 in the form of a cotton swab that can be easily removed by opening the cap 40.

[0049] The sample tube 32 contains the buffer solution 7. It is provided that the sample tube 32 be placed in the sample holder 203 after being removed from the fixing device 21. Thus, the user of the test kit 1 has his or her hands free when performing the detection reaction.

[0050] Acetylcholinesterase is located in the reagent cap 42 as the first active component, and Ellman's reagent and acetylthiocholine are located in the reagent cap 43 as the second active component. Both active components are present in solid form. The tubes 33, 34 serve only for shielding the active components in the caps 43, 44 such that they cannot become contaminated or fall out. In the embodiment shown, the tubes 33, 34 also contain desiccants 50, 51 in bag form.

[0051] The cap holders 201, 202 are used to prepare the performance of the detection reactions and/or to deposit the empty caps after the active components have been dissolved out.

[0052] In the embodiment shown in FIG. 2, the individual components or the sample tubes 30, 32, 33, 34 are arranged from left to right in the sequence according to FIG. 1 that is required for carrying out the detection. This facilitates the performance of the detection and serves to minimize user errors.

[0053] FIG. 3 is a schematic representation of the support apparatus 2 already shown in FIG. 2. In the embodiment shown here, the fixing devices are designed as a clamping device and comprise the depressions 20, 21, 22, 23 and the recesses 204, 205, 206. The depressions 20, 21, 22, 23 serve to receive the sample tubes 30, 32, 33, 34 and have a profile in the shape of a circular arc.

[0054] In the embodiment shown, the support apparatus has a length 11 of 80 mm and a length 13 of 50 mm, and is thus very compact. The diameter d1 of the cap holders 201, 202 is 15 mm, and the diameter d2 has a diameter of 12 mm. Thus, the support apparatus is particularly suitable for sample tubes having a diameter in the range of 10 to 12 mm.

[0055] FIG. 4 is a schematic representation of a cross-section through the fixing device of a support apparatus 2 as shown in FIG. 3. In this case, the chord length b of the circular arc is smaller than the diameter of the circle d3, and the arc length is greater than half the circumference. Due to this profile, the sample tubes can be fixed with corresponding diameters by clamping the sample tubes. Through the recesses 204, 205, 206 between the depressions 20, 21, 22, 23, clamping wings 26 are formed, which ensures the flexibility of the fixing device required for clamping the sample tube. The length 12 of the depressions 20, 21, 22, 23 is preferably smaller than the length of the sample tubes 30, 32, 33, 34. In this case, the diameter of the sample tubes corresponds to the diameter d3 or is slightly smaller.

[0056] FIG. 5 is a schematic representation of a cross-section through a partial region of a support apparatus 2 as shown in FIG. 3. In this case, the partial region shown in FIG. 5 comprises the cap holders 201 and 202 and the sample holder 203. Both cap holders 201, 202 and the sample holder 203 are formed by recesses in the upper side 18 of the support apparatus 2. In the embodiment shown in FIG. 5, the cap holders 201, 202 have a depth h1, and the sample holder 203 has a depth h2, wherein the depth h2 is greater than the depth h1. The cap holders 201, 202 are thus flatter than the sample holder 203. In other words, the sample holder 203 is preferably designed with a greater depth than the cap holders 201, 202—in particular, also in order to ensure secure reception of the sample tube in the receiving device. Both the cap holders 201, 202 and the sample holder 203 have a depth that is less than the thickness h of the support apparatus. Thus, the embodiment shown in FIGS. 3 through 5 has a closed underside. This is advantageous because both the cap and the sample tube are thus fixed independently of the respective substrate on which the support apparatus 2 is placed.

[0057] FIG. 6 is a schematic representation of the cutout shown in FIG. 5, in which the caps 42, 43 were positioned in the cap holders 201 and 202. The sample tube 30 with the buffer solution 7 is inserted in the sample holder 203.

[0058] FIG. 7 shows a photograph of an embodiment in which the test kit 1 is packaged in an outer film packaging 12. By using the support apparatus 2 according to the invention, the test kit 1 can be packaged flat. On the outer packaging 12, a label 13 is expediently located on one side (front or rear side), which label contains a brief description and an instruction diagram for performing the test. A label having the relevant information (e.g., designation, production, batch no., durability) and/or the color scale is expediently located on the other side of the outer packaging 12 (consequently, not visible in FIG. 7). Because the test kit is flat, the labels can easily be read before the test kit is removed from the outer packaging.

[0059] FIG. 8 is a photograph showing the state of the test kit 1 after removal from the outer packaging. By fixing the individual sample tubes, not only can the dimensions of the test kit be minimized, but the individual components of the test kit are also presented to the user in a very clear manner. Changing the components is also avoided by the fixing of the individual components by the support apparatus. In the embodiment shown in FIG. 8, the individual components are again arranged, corresponding to FIG. 2, from left to right in the order required for the test. This also simplifies use and minimizes user errors.

[0060] FIG. 9 shows a photograph of the embodiment shown in FIG. 8 in which the individual components were arranged in the support apparatus in preparation for the performance of the test. The reagent caps having the active components acetylcholinesterase, DTNB, and acetylthiocholine were placed in the cap holders of the support apparatus. The sample tube was inserted into the sample holder. The user can thus remove the sample with the sampling device and concentrate on performing the detection reaction without searching for and/or unpacking the individual components between the individual steps.

[0061] Because the support apparatus forms secure storage for sample tubes and the caps having the active components, contamination or spillage can be avoided—particularly in the case of turbulent use environments.

[0062] FIGS. 10 and 11 show photographic images of a known test kit as a comparison. FIG. 10 shows the test kit in an outer film packaging 14. As a result of the loose arrangement of the individual components, the outer packaging 14 has a distinct curvature. FIG. 11 shows the individual components, consisting of sample tubes having a buffer solution 15, a shrink-wrapped sampling device 16, and a film-heat-sealed outer packaging 17 that contains the reagent caps having the active components acetylcholinesterase, DTNB, and acetylthiocholine.

LIST OF REFERENCE NUMERALS

[0063] 1 test kit [0064] 2 carrier [0065] 6 sampling device [0066] 7 buffer solution [0067] 8 sample [0068] 10 sample solution having acetylcholinesterase [0069] 11 test solution having the sample solution 10, 5,5′-dithiobis(2-nitrobenzoic acid) and acetylthiocholine [0070] 12 outer packaging [0071] 13 label [0072] 14 outer packaging comparative example [0073] 15 test solution of the comparative example [0074] 16 shrink-wrapped sampling device of the comparative example [0075] 17 shrink-wrapped cap of the comparative example [0076] 18 upper side of the support apparatus [0077] 19 underside of the support apparatus [0078] 20, 21, 22, 23 fixing device [0079] 30, 32, 33, 34 sample tube [0080] 40, 41 cap [0081] 42 reagent cap having acetylcholinesterase [0082] 43 reagent cap having 5,5′-dithiobis(2-nitrobenzoic acid) and acetylthiocholine [0083] 50, 51 desiccant [0084] 201, 202 receiving device for reagent cap [0085] 203 sample holder [0086] 204, 205, 206 recess