CN114705851A

CN114705851A - Immunodetection device

Info

Publication number: CN114705851A
Application number: CN202210297650.1A
Authority: CN
Inventors: 商涛; 费凤琴; 蔡政君; 孔健希; 郑珍珍; 童芳丽
Original assignee: Acon Biotech Hangzhou Co Ltd
Current assignee: Acon Biotech Hangzhou Co Ltd
Priority date: 2022-03-24
Filing date: 2022-03-24
Publication date: 2022-07-05
Also published as: WO2023179215A1

Abstract

The invention relates to an immunodetection device, which comprises an upper cover, a bottom plate and a test strip, wherein the upper cover is buckled with the bottom plate, and the test strip is positioned between the upper cover and the bottom plate. The test strip is provided with a sample adding pad, and the two sides of the sample adding pad of the test strip are provided with liquid storage tanks on the bottom plate for absorbing redundant liquid samples. The invention can effectively avoid the flooding phenomenon when adding excessive liquid samples, and is beneficial to improving the success rate of detection. The invention has the advantages of simple operation, convenient use, quick detection result and the like, and is particularly suitable for batch investigation and detection of infectious diseases such as novel coronavirus and the like.

Description

Immunodetection device

Technical Field

The invention relates to a detection device, in particular to an immunodetection device.

Background

Lateral Flow Test strips (Lateral Flow Test strips) are currently common rapid detection products, and realize the transmission of a sample on the Test strips by using an immunochromatography principle and obtain a detection result. The lateral cross-flow test strip generally includes a bottom card, on which a sample pad, a label binding pad (also called a label pad for short, usually using glass fiber as a carrier), a test pad (usually using NC membrane as a carrier), and a water absorption pad (usually using water-absorbing materials such as filter paper) are adhered, which are sequentially stacked one on another from upstream to downstream. The label pad includes a label capable of binding to an analyte, such as latex, colloidal gold, fluorescent microspheres, etc. labeled with an antigen or an antibody. The test pad is generally provided with a detection line and a quality control line. Depending on the reaction principle, as the sample flows on the test strip, the label may be captured and accumulated or not captured on the detection line. The presence or concentration of the analyte is determined based on a signal from the label, such as a color signal or a fluorescent signal. The quality control line can be used for judging whether the test paper is effective or for positioning when an instrument reads a detection result and the like.

In some test devices, the test strip is typically mounted in a test plate. The detection plate comprises an upper cover and a lower plate, the upper plate is provided with a sample adding hole and an observation window, and the test paper strip is arranged between the upper cover and the lower plate. After the liquid sample is dripped in the application of sample hole of pick-up plate, if the volume of liquid sample is great, can lead to a large amount of samples to gush into the draw-in groove on the hypoplastron to cause the flood phenomenon (flood phenomenon), thereby influence the normal work of test paper strip. The flooding phenomenon appears as: the sample directly reaches the test strip to cause the sample to directly overflow a detection area of the test strip; or the liquid sample quickly runs to the filter paper of the test paper along the edge or other frame of the bottom plate under the capillary action and is absorbed by the filter paper. This portion of the liquid sample is faster than the liquid flowing through the marker pad, NC membrane. The liquid sample absorbed by the filter paper in advance flows reversely to the NC membrane, thereby affecting the normal operation of the test paper.

The present invention has been made in view of such circumstances.

Disclosure of Invention

In order to solve the technical problem, the invention provides an immunoassay device, which comprises an upper cover, a bottom plate and a test strip, wherein the upper cover is combined with the bottom plate in a buckling manner, the test strip is arranged on the bottom plate and is positioned between the upper cover and the bottom plate, the test strip comprises a longitudinal strip-shaped hard bottom card and a sample adding pad, an immunoassay reagent identification pad, a detection result display pad and a water absorption pad which are positioned on the hard bottom card and are sequentially connected in pairs along the longitudinal direction of the hard bottom card, the sample adding pad, the immunoassay reagent identification pad, the detection result display pad and the water absorption pad are all made of water-absorbent materials, the upper cover comprises sample adding holes corresponding to the sample adding pad of the test strip, liquid storage tanks are arranged on two sides of the sample adding pad of the test strip by the bottom plate, and the bottoms of the liquid storage tanks are lower than the bottom surfaces of the test strip. .

As a further improvement of the invention: the bottom plate is provided with a dam forming a reservoir, the bottom of the dam being lower than the bottom surface of the test strip.

As a further improvement of the invention: the bottom plate is provided with a raised part on which the test strip is located.

As a further improvement of the invention: the elevating member is provided with a slope on which the test strip is fixed at the end of the sample application pad by the projection on the bottom plate, and the end of the test strip at the end containing the sample application pad is lower than the immunoreagent-labeled pad.

As a further improvement of the invention: two ends of the dam are respectively connected with the heightening component and the side plate of the bottom plate, so that the liquid storage tank is formed together.

As a further improvement of the invention: the bottom plate and the upper cover are provided with misplug prevention structures at corresponding positions, and the upper cover can be combined with the bottom plate only when the sample adding hole of the upper cover is positioned right above the sample adding pad of the test strip.

As a further improvement of the invention: the misplug prevention structure comprises a protrusion matching recess and a protrusion matching protrusion, wherein the protrusion matching recess is arranged at the corresponding position of the same side of the upper cover and the bottom plate, and the protrusion matching protrusion is arranged at the corresponding position of the different side of the upper cover and the bottom plate.

As a further improvement of the invention: the misplug prevention structure is in an asymmetric structure on two sides of the immunity detection device relative to the longitudinal center line of the immunity detection device.

Advantageous effects

The invention has the beneficial effects that: when the liquid sample is applied to the sample adding pad on the test strip through the sample adding hole of the upper cover, the liquid sample diffuses on the sample adding pad and is transmitted to the immunoreagent identification pad connected with the sample adding pad, and then is continuously transmitted to the detection result display pad connected with the immunoreagent identification pad, and finally reaches the water absorption pad. When the amount (volume) of the added liquid sample exceeds the amount required by detection, the liquid sample absorbed by the pads reaches a saturated state, at this time, the pads cannot generate enough power to push the redundant liquid sample to continue flowing along the initial liquid flowing direction, and the redundant liquid sample leaks downwards from the two sides or the end parts of the sample adding pad and falls into the liquid storage tanks on the two sides of the sample adding pad. The dam blocks the liquid sample in the liquid storage tank, and can not flow into the end where the absorbent pad of the test strip is located, so that the phenomenon of Flooding caused by the redundant liquid sample is prevented, and the success rate of the detection result and the accuracy of the detection result are improved.

Drawings

FIG. 1 is a schematic perspective view of an immunoassay device of the present invention;

FIG. 2 is a top view of FIG. 1;

FIG. 3 is an exploded perspective view of FIG. 1;

FIG. 4 is a top view of the upper cover of the immunoassay device of the present invention;

FIG. 5 is a bottom view of the upper cover of the immunoassay device of the present invention;

FIG. 6 is a perspective view of the bottom plate of the immunoassay device of the present invention;

FIG. 7 is a top view of the bottom plate of the immunoassay device of the present invention;

FIG. 8 is a schematic perspective view of a test strip of the immunoassay device of the present invention;

FIG. 9 is an exploded perspective view of FIG. 8;

FIG. 10 is a schematic perspective view of the immunoassay device of the present invention with the cover removed;

FIG. 11 is a top view of FIG. 10;

FIG. 12 is a cross-sectional view (test strip not cut) of FIG. 11 taken along longitudinal centerline C-C thereof;

FIG. 13 is an enlarged partial view of portion "A" of FIG. 10;

FIG. 14 is an enlarged partial view of the portion "B" of FIG. 12;

FIG. 15 is a schematic view of the immunoassay device of the present invention after the excess liquid sample is added and the excess liquid sample overflows from the sample application pad of the test strip (the upper cover is removed for easy observation);

FIG. 16 is a schematic view showing the immunoassay device of the present invention with its upper cover assembled to the lower plate in the correct orientation;

FIG. 17 is a schematic view showing an immunoassay device of the present invention with its upper cover assembled to the lower plate in a wrong orientation.

Detailed Description

The technical scheme of the invention is further specifically described by the following embodiments and the accompanying drawings.

Referring to fig. 1-17, the present invention provides an immunoassay device 1 comprising a top cover 10, a bottom plate 20 and a test strip 30, wherein the top cover 10 is combined with the bottom plate 20 by means of snap-fit, welding, glue bonding, etc., and the test strip 30 is disposed on the bottom plate 20 and between the top cover 10 and the bottom plate 20.

Referring to fig. 8 and 9, the test strip 30 is elongated. The test strip 30 includes a sample application pad 31, an immunoreagent identification pad 32, a detection result display pad 33, and a water absorption pad 34 connected in pairs in sequence along the longitudinal direction (i.e., the direction indicated by the arrow "D" in fig. 8). The sample addition pad 31, the immunoreagent labeling pad 32, the detection result display pad 33, and the water absorption pad 34 are all water-absorbent materials. The pads 31 to 34 are adhered to a rigid card 35 in the form of an elongate strip. In a preferred embodiment, these pads 31-34 are connected in an end-to-end overlapping manner (i.e., the manner shown in FIG. 8) so that when an appropriate amount of a liquid sample for testing is applied to a predetermined area of the sample application pad 31, the liquid sample will flow through the

pads

31, 32, 33 and 34 in sequence in the direction indicated by arrow "D" and will eventually be absorbed by the bibulous pad 34. During the flowing process of the liquid sample, the labeled reagent labeled on the label pad 32 in advance is dissolved, and then the liquid sample continues to flow in the direction indicated by the arrow "D", and when it flows through the test result display pad 33, the analyte and the labeled reagent in the liquid will be captured by the T line (detection line) and C line (quality control line) areas provided on the pad 33 in advance and then show color, thereby determining whether the test result is negative, positive or invalid. In general, a, if no color is displayed in the C line area, the detection is invalid, and the detection needs to be carried out again; b. if the color is displayed in the C line area and the color is not displayed in the T line area, the detection result is negative; c. if the color is displayed in the C line area and the T line area, the detection result is positive.

Referring to fig. 1, 2, 3 and 4, the upper cover 10 includes a sample application hole 11 and a observation hole 12 corresponding to the sample application pad 31 and the detection result display pad 33 of the test strip 30, respectively. The liquid sample for detection is applied to the sample addition member 31 via the sample addition hole 11. After the detection is completed, the color change in the T-line and C-line regions on the detection result display pad 33 is observed through the observation hole 12, and the detection result is determined based on this (determination method is as described above). In another embodiment, the observation hole 12 may be a transparent window instead of a hole, and any structure may be used as long as the color change of the T-line and C-line regions on the display pad 33 can be observed.

Referring to fig. 6, 7, and 10-15, the bottom plate 20 is provided with a liquid reservoir 21 on each side of the sample loading pad 31 of the test strip 30, and the bottom 22 of the liquid reservoir 21 is lower than the bottom 36 of the test strip 30. The base plate 20 is provided with a dam 23 forming a reservoir 21, the bottom of the dam 23 being the bottom 22 of the reservoir 21, and thus the bottom of the dam 23 is also lower than the bottom surface 36 of the test strip 30. Two reservoirs 21 are shown on each side of the test strip 30 in fig. 6, 7 and 10, but there may be only one or more than two reservoirs on each side. The base plate 20 is provided with an elevation feature 24 (shown in fig. 6) and the test strip 30 is positioned on the elevation feature 24 (shown in fig. 10, 12, 13, 14).

The heightening member 24 is provided with a slope 25. The test strip 30 is held on the ramp 25 at the end of the strip 31 by the protrusion 26 on the base 20 (fig. 13), so that the end 37 of the strip 30 containing the sample pad 31 is lower than the immunoreagent label pad 32, i.e., the end 37 of the sample pad 31 is bent downward at an appropriate angle when viewed from the side (fig. 14). The advantages of this design are: after the liquid sample is applied to the sample addition member 31, the liquid sample is first climbed and then transferred to the pad 32, the pad 33, and the pad 34 in this order, thereby facilitating control of the transfer rate of the liquid sample.

As shown in fig. 6 and 7, both ends of the dam 23 are connected to the elevation member 24 and the side plate 27 of the bottom plate 20, respectively, thereby forming the reservoir 21 together.

The beneficial effect that above-mentioned structure was brought is: when a liquid sample is applied to the sample addition member 31 of the test strip 30 through the sample addition hole 11 of the upper cover 10, the liquid sample spreads on the sample addition member 31 and is transferred to the immunoreagent label pad 32 connected to the sample addition member 31, and then is transferred to the detection result display member 33 connected to the immunoreagent label pad 32, and finally reaches the absorbent member 34. Normally, the force of the liquid sample on the test strip 30, which is transmitted from the sample application pad 31 to the pad 32, the pad 33 and the pad 34 in turn, comes mainly from the pulling force of the absorbent pad 34 (because the absorbent capacity of the absorbent pad 34 is far higher than that of the pad 32 and the pad 33). However, in the case of the conventional detection apparatus, when the amount (volume) of the liquid sample added exceeds the amount required for detection, the liquid sample flows from the sample addition member 31 to the bottom plate 20, and then directly reaches the absorbent member 34 bypassing the pad 32 and the pad 33. Absorbent pad 34 will now compete with

pads

32 and 33 and absorb a significant amount of the liquid sample at a much faster rate than

pads

32 and 33, resulting in saturation of the liquid sample before

pads

32 and 33 are not saturated, at which point pad 34 has no power to pull the liquid sample along

pads

31, 32, 33 and 34 in sequence, and will instead cause the liquid sample to flow back from pad 34 toward

pads

33 and 32 because pad 34 is first saturated with the liquid sample. Since the liquid sample flowing backward in the reverse direction does not dissolve the labeled reagent on the immunoreagent labeled pad 32, when it reaches the test result display pad 33, no labeled reagent is combined with the detection reagent on the pad 33, and therefore, even a positive sample cannot display a colored indication line, thereby giving an erroneous test result, which is a phenomenon called Flooding (Flooding) in the art. In the present invention, the excess liquid sample 50 leaks downward from both sides or end portions 37 of the sample addition member 31, and falls into the reservoirs 21 on both sides of the sample addition member 31 (as shown in FIG. 15). The dam 23 blocks the liquid sample in the liquid storage tank 21, and the liquid sample does not flow into the end of the test strip 30 where the absorbent pad 34 is located, and the liquid sample does not bypass the pad 32 and the pad 33 to reach the pad 34, so that the excessive liquid sample 50 is prevented from generating a Flooding phenomenon (Flooding), and the success rate of the detection result and the accuracy of the detection are improved.

Referring to fig. 16 and 17, another improvement of the present invention is: the base plate 20 and the upper cover 10 are provided with an erroneous insertion preventing structure at corresponding positions. The erroneous insertion preventing structure includes a protrusion 28 mating recess 29 provided at a corresponding position on the same side (T) of the upper cover 10 and the bottom plate 20, respectively, and a protrusion 28 mating protrusion 28 provided at a corresponding position on the opposite side (Y) of the upper cover 10 and the bottom plate 20, respectively. The cover 10 can be snap-coupled to the base plate 20 only when the wells 11 of the cover 10 are positioned directly above the sample application pads 31 of the test strip 30, the projections 28 of the cover 10 correspond to the recesses 29 of the base plate, and the recesses 29 of the cover 10 correspond to the projections 28 of the base plate (see fig. 16). Conversely, when the cover 10 is turned 180 degrees to make the sample adding hole 11 on the cover directly above the absorbent pad 34 of the test strip, the protrusion 28 of the cover 10 corresponds to the protrusion 28 of the base plate, and at this time, the two protrusions 28 will abut against each other, so that the cover 10 cannot be snapped to the base plate 20 (as shown in fig. 17), thereby giving a signal of misinsertion, and prompting the operator to turn 180 degrees to snap the cover 10 onto the base plate 20. As is apparent from fig. 16 and 17, the anti-misinsertion structure is asymmetric on both sides of the immunoassay device 1 with respect to the immunoassay device at its longitudinal centerline (e.g., line C-C in fig. 11).

The invention has the beneficial effects that the misplug prevention structure is arranged: the operator does not need to carefully distinguish the shapes of the upper cover 10 and the bottom plate 20 (in fact, the difference between the shapes of the bottom plate 20 in the normal position and the abnormal position after being turned over by 180 degrees is not obvious and is difficult to be distinguished quickly), and even does not need to observe the placing positions of the upper cover 10 and the bottom plate 20, the operator only needs to align the upper cover and the bottom plate along the longitudinal direction and then press the upper cover to the bottom plate, if the upper cover and the bottom plate can be smoothly buckled, the buckling mode of the upper cover and the bottom plate is correct, and the product is a qualified product. On the contrary, if the upper cover can not be smoothly snapped onto the bottom plate, the way of snapping the upper cover and the bottom plate is wrong, and at this time, the operator needs to turn the upper cover 180 degrees to smoothly snap onto the bottom plate 20, and the product is still a qualified product. Therefore, the misplug prevention structure provided by the invention has the advantages that the burden of an operator is reduced (the operator does not need to carefully observe whether the placement direction of the upper cover is correct or not), the working efficiency of the operator is improved, and the qualification rate of products is improved. However, in the existing products without the misplug prevention structure, when the upper cover is inserted into the bottom plate in an abnormal orientation after being turned over by 180 degrees, the upper cover still can be buckled to the bottom plate, but the sample adding hole of the upper cover is opposite to the sample adding pad on the test strip but is a water absorption pad on the test strip, and obviously, the product is an unqualified product. Therefore, compared with the prior art, the invention improves the qualification rate of products. The more adverse consequences of this off-spec product are: since the product fails to give an unqualified signal, the operator does not know that the product is mistakenly regarded as a qualified product (difficult to find by naked eyes), and the qualified product is delivered to an inspector for use. When a tester applies a liquid sample to the sample adding hole of the upper cover for detection, the product cannot give a correct detection result, so that the detection fails, and the sample needs to be re-extracted and replaced by a qualified product for re-detection. Therefore, a great waste of manpower and material resources is caused, which has adverse consequences.

The invention can be used for detecting the antigen of the novel coronavirus (SARS-CoV-2) and other epidemic infectious diseases viruses. The immune detection device adopts lateral cross flow technology, the immune reagent mark pad 32 comprises anti-novel coronavirus (anti-SARS-CoV-2) antibody-latex marker, the detection line (T line) on the detection result display pad 33 is coated with anti-SARS-CoV-2 antibody, and the quality control line (C line) on the detection result display pad 33 is coated with goat anti-mouse IgG. The prepared detection test paper can also be assembled in a detection plate for use. The novel coronavirus (SARS-CoV-2) antigen test paper can be used for quick screening and shunt management of people to shorten the propagation chain, and has the advantages of quickness, simplicity and easiness in operation. The person who has a positive detection result can also be required to perform nucleic acid detection again for rechecking.

The above description is only a specific embodiment of the present invention and does not therefore limit the scope of the invention as claimed. All equivalent structures or equivalent processes performed by using the contents of the specification and the drawings of the present invention, or directly or indirectly applied to other related technical fields, shall be included in the scope of the present invention.

Claims

1. An immunoassay device, comprising: including upper cover, bottom plate and test strip, the upper cover combines with the bottom plate buckle, the test strip is settled on the bottom plate and is located between upper cover and the bottom plate, the test strip includes the banding stereoplasm end card of lengthwise and is located this stereoplasm end card and along its lengthwise direction in proper order two liang of sample addition pad, immunoreagent identification pad, testing result display pad and the pad that absorbs water of connecting, sample addition pad, immunoreagent identification pad, testing result display pad and the pad that absorbs water are water-absorbing material, and the upper cover is equipped with the liquid storage tank including the application of sample hole that corresponds to the sample addition pad of test strip, and the bottom of bottom plate at the sample addition pad of test strip is less than the bottom surface of test strip.

2. The immunoassay device of claim 1, wherein: the bottom plate is provided with a dam forming a liquid storage tank, and the bottom of the dam is lower than the bottom surface of the test strip.

3. The immunoassay device of claim 2, wherein: the bottom plate is provided with a heightening part, and the test strip is positioned on the heightening part.

4. The immunoassay device of claim 3, wherein: the elevating part is provided with a slope, the test strip is fixed on the slope by the protrusion on the bottom plate at the end of the sample adding pad, and the end of the test strip containing the sample adding pad is lower than the immune reagent identification pad.

5. The immunoassay device of claim 4, wherein: two ends of the dam are respectively connected with the heightening component and the side plate of the bottom plate, so that the liquid storage tank is formed together.

6. The immunoassay device of claim 1, wherein: the bottom plate and the upper cover are provided with misplug prevention structures at corresponding positions, and the upper cover can be combined with the bottom plate only when the sample adding hole of the upper cover is positioned right above the sample adding pad of the test strip.

7. The immunoassay device of claim 6, wherein: the misplug prevention structure comprises a protrusion matching recess and a protrusion matching protrusion, wherein the protrusion matching recess is arranged at the corresponding position of the same side of the upper cover and the bottom plate, and the protrusion matching protrusion is arranged at the corresponding position of the different side of the upper cover and the bottom plate.

8. The immunoassay device of claim 7, wherein: the misplug prevention structure is in an asymmetric structure on the two sides of the immunity detection device relative to the longitudinal center line of the immunity detection device.