CN104977402A - A test strip for testing samples - Google Patents

Abstract

The invention relates to a test strip for detecting a sample, which comprises a marking pad and a detection pad, wherein the detection pad is positioned at the downstream of the marking pad. The test strip of the invention enables the release speed of the gold label to be slowed down and buffered because the marking pad is covered by the sample pad, thereby increasing the concentration ratio of the analyte to the gold label antibody in the sample and improving the detection sensitivity of the test strip. Meanwhile, the outer layer of non-setting adhesive is separated from the inner layer of the marking pad, so that the test strip does not cause the difference of the heights of the two sides of the marking pad or reduce the difference of the heights of the two sides of the marking pad in the production process, the speed of the sample flowing through the marking pad is ensured to be the same, and the analyte in the sample and the antibody with the gold mark can be combined in a component manner. Finally, the phenomena of line breakage and color difference of the test structure line are effectively reduced.

Description

A test strip for testing samples

technical field

The invention relates to a device for detecting samples, especially a test strip for detecting samples. the

Background technique

The technique of using the principle of immunological binding reaction to detect the presence or absence of analyte in a sample is widely used in various fields. It can be used to detect analytes in various biological samples (saliva, blood, urine, serum, sweat, etc.) to monitor diseases and human health conditions (early pregnancy, tumors, infectious diseases, drugs, etc.). The fundamental principle of this detection technology is based on the specific binding properties between immune molecules, such as antibody and antigen, hapten/antibody, biotin and anti-biotin, etc. In addition, many of these assays can be performed on solid media, such as commonly used lateral flow reagent strips, glass or plastic multiwell plates, immunochromatographic devices, and the like. Usually, some solid particles or chemical substances can be combined on the immunospecific binding molecules, so that qualitative, quantitative or semi-quantitative detection results can be obtained by naked eyes or other instruments and equipment. The solid particles can be colored colloidal particles (latex or gold particles), and the chemical substances can be substances with chromophores that, under other suitable conditions, emit specific wavelengths to reveal detection results. the

Detection reagent strips or devices using these principles can be found in the prior art, such as the reagent strips or devices containing reagent strips described in the following patents: US4857453; US5073484; US5119831; US5185127; US5275785; ；US5654162；US5656503；US5686315；US5766961；US5770460；US5916815；US5976895；US6248598；US6140136；US6187269；US6187598；US6228660；US6235241；US6306642；US6352862；US6372515；US6379620；和US6403383。 the

Immunoassays usually include two principles, sandwich method and competition method, among which the competition method is the most common method for detecting hapten small molecules in samples. The methods, reagents and detection devices using the competition method are described in detail in US Pat. No. 4,235,601; US Pat. These devices all describe that when there is no color change or no color lines appear on the detection area or the result reading area, the test result is judged as positive, indicating that the analyte may exist in the test sample. On the contrary, when the detection area or the result reading area When there is a color change or a colored line appears on the area, the test result is judged as negative, indicating that the analyte may not exist in the test sample. the

Therefore, the display of the control line and/or the detection result line in the detection area on the test strip is used to detect whether there is a certain analyte in the sample. However, when these test strips are actually used to detect analytes in samples, there are some problems:

After the sample is added to the marking pad, due to the concentration of the added amount and the fast flow of the liquid, the sample and the markers on the marking pad are quickly rushed to the detection pad, that is, a large number of markers are brought to the detection pad, which makes the detection pad. The detection sensitivity is reduced. Especially for the test strips tested by the competition method, the final result shows that the gradient difference between negative and positive is small, and in the case of positive, there will be a shallow test line display. This interferes with the judgment of the results, especially since the operators of the test strips are usually the general public. the

Because the test strips are mass-produced, each test strip needs to be cut during the production process, and after cutting, the sticker on the surface of the test strip is different due to the force on both sides of the blade, causing the two sides of the test strip to Adhesives are different from sample pads, marking pads, etc. In general, one side of the test strip (such as the left side) is tightly bonded to the labeling pad, while the other side (such as the right side) is due to the force Unlike, the bond is loose. In this way, when the sample is detected, the flow rate of the sample on the marker pad is different due to the different thickness of the marker pad, resulting in uneven binding of the gold-labeled antibody to the analyte in the sample, which will eventually lead to the display of the test result—the detection line or The control line is broken, that is, the line is not completely displayed. At the same time, there are also differences in the test results when the same sample is tested with the same batch of test strips. Thus, the reading and judgment of the detection results are seriously affected. the

Contents of the invention

In order to solve these problems, the present invention provides test strips with different structures, which can make the positive substances in the sample bind to markers, the ratio of the positive substance concentration to the gold-labeled antibody concentration will be greater than the conventional result The test strip can make the positive substance and the labeled substance more fully combined, and finally the substance on the test pad that competes with the positive substance cannot be combined, so that the detection result of the positive substance is more obvious, so that the detection sensitivity of the test strip is higher; Moreover, this improved structure can make the outer sticker of the test strip not connected to the marking pad, thereby overcoming the problem of different heights on both sides of the marking pad, and solving the problem of disconnection or difference in test results. the

A test strip for detecting samples provided by the present invention includes a marking pad and a detection pad, the detection pad is located downstream of the marking pad, wherein the test strip also includes a sample pad, and the sample pad will mark Pads are fully or partially covered. After the sample pad covers part or all of the marker pad, when the sample is added to the sample pad, the sample moves downstream along the sample pad. During the movement, it touches the marker pad. If there is a positive analyte in the sample, the positive marker The substance contacts and binds to the marker on the marker pad (that is, the antibody on the marker), and the combined positive analyte then travels along the sample pad to the detection pad for detection. Because the marker is fully combined with the positive analyte, it can no longer Combined with the antigen on the test pad, thus, no label will be trapped, and therefore no test result line will be displayed. Because the sample pad is covered on the marking pad, the sample on the sample pad contacts and binds to the marking substance below it during the flow process, and the sample is not added to the marking pad in large quantities quickly, so the marker achieves slow release. As a result, the marker and the positive substance in the sample can have sufficient time to fully contact and combine. Instead of being washed up together as in ordinary test strips, it is equivalent to releasing most of the markers at the first time. Even if there are many positive substances, it is too late to fully combine with all the labeled antibodies released at the same time. As a result, part of the labeled antibody flows to the detection pad to combine with the detected antigen, and the result line will be displayed, that is, a false negative is formed, which affects the sensitivity of the test and the judgment of the test result. That is, when a positive sample is combined with a slow-release labeled antibody, the time for the same label to be released is prolonged, which is equivalent to an increase in the ratio of the concentration of the positive substance to the concentration of the gold-labeled antibody, which is greater than that of the test strip for conventional results The ratio when the two are combined during the detection process makes the detection sensitivity of the test strip higher. the

More specifically, the sample pad covers part or all of the marking pad means that the part of the marking pad with the marker is completely or partially covered by the sample pad. In this way, when the sample flows through the sample pad, the label on the portion of the pad that is in contact with the sample pad is released into the sample pad to contact and bind to the analyte in the sample. the

In a preferred embodiment, the sample pad is connected to the detection pad. In this way, the labeled antibody on the marker pad combines with the positive substance of the sample on the sample pad and then flows along the sample pad to the detection pad for the next step of detection. the

In some embodiments, the marker pad and the detection pad can be connected. the

In other preferred embodiments, there is a certain distance between the marking pad and the detection pad. the

The marker pad and the detection pad may or may not be connected. When the marker pad is connected to the detection pad, the marker may flow directly onto the detection pad, which will affect the detection result; In this way, the time and space for the positive substances in the sample to fully combine with the markers are given, which is more conducive to the display of the test results and improves the sensitivity of the test. the

In another specific preferred embodiment, the sample pad separates the marker pad and the detection pad. That is, the sample pad is located within the space between the marker pad and the detection pad. On the other hand, the sample pad is located within this interval, communicating with the marker pad and the detection pad. the

In another embodiment, the sample pad is divided into two parts: a first sample pad and a second sample pad. the

Specifically, the first sample pad is connected to the second sample pad; the connection point between the first sample pad and the second sample pad is located upstream of the marking pad. More specifically, the first sample pad is connected to one end of the second sample pad. the

More specifically, the second sample pad covers the marker pad. That is, the second sample pad covers part or all of the marker pad, that is, the second sample pad covers part or all of the marker pad on the marker pad. the

Preferably, the second sample pad is connected to the detection pad. More specifically, the other end of the second sample pad is connected to the detection pad. That is, the first sample pad and the detection pad are respectively connected to two ends of the second sample pad. the

In some embodiments, the test strip also includes an outer layer of self-adhesive. the

In a specific embodiment, the outer layer of self-adhesive is covered on the detection pad and the sample pad above the marking pad; the sample pad separates the outer layer of self-adhesive and the marking pad. the

The sample pad is covered on the marking pad so that the outer layer of self-adhesive is not directly connected to the marking pad, so that the stickiness of the self-adhesive will not affect the marking pad. Therefore, in the process of cutting the test strip, the marking pad will not cause uneven thickness of each part due to uneven force on both sides of the test strip (especially the difference in thickness of the marking pads on the two sides of the test strip) larger). When the thickness of the marking pad is uniform, the flow rate of the fluid flowing through the marking pad is also uniform, and the reaction with the gold standard marker is also uniform, so that the test results in the next step are also displayed uniformly, avoiding the test results on the same test strip. The line phenomenon and the test results of different test strips show that the color has color difference. the

In some embodiments, the material of the sample pad is polyester fiber membrane or nitrocellulose membrane, glass fiber membrane or filter paper. Particularly, in a specific embodiment, the first sample pad is made of glass fiber membrane; the second sample pad is made of filter paper. the

Beneficial effect

Because the test strip of the present invention is covered by the sample pad, the release speed of the gold label is slowed down and buffered, thereby increasing the concentration ratio of the analyte in the sample to the gold-labeled antibody, thereby improving the detection efficiency of the test strip. sensitivity. At the same time, the outer layer of self-adhesive is separated from the inner layer of the marking pad, so that the test strip will not cause the height difference between the two sides of the marking pad during the production process or reduce the phenomenon that the height of the two sides of the marking pad is different, ensuring that the sample flows through The same speed is used when labeling the pad, allowing the analyte in the sample to bind to the gold-conjugated antibody. In the end, the broken line and color difference phenomenon of the test structure line are effectively reduced. the

Description of drawings

Fig. 1 is the structural representation of common test strip;

Fig. 2 is the structural representation of an improved test strip of the present invention;

Fig. 3 is the structural representation of another improved test strip of the present invention;

Fig. 4 is a structural schematic diagram of another improved test strip of the present invention. the

Explanation of reference signs:

Test strips 100, 200, 300, 400; sample pads 120; outer stickers 110, 210; marker pads 130, 230; test pads 140, 240; absorbent pads 150, 250; bottom sheets 160, 260; test Result C line 142,244; test result T line 141,243; sample pad 220; first sample pad 222; second sample pad 221; distance 270 between marker pad and test pad; Marker pad one end 231 ; sample pad one end 225 . the

Detailed ways

The structures involved in the present invention or the technical terms used are further described below. the

test strip

The reagent strip 100 used in the present invention may be a so-called lateral flow reagent strip, and the specific structure and detection principle of these reagent strips are well known to those skilled in the art in the prior art. A common reagent strip includes a sample collection area, a marking area, a detection area and a water absorption area. The sample collection area includes a sample pad, the marking area includes a marking pad, and the water absorption area can include a water absorption pad. Whether it contains the necessary chemical substances of the analyte, when the test is over, a test line and a control line indicating the result will appear on the test area. The commonly used detection reagent strips are nitrocellulose membrane reagent strips, that is, the detection area includes nitrocellulose membrane (NC membrane), and specific binding molecules are immobilized on the nitrocellulose membrane to display the detection results. It can also be a cellulose acetate membrane. Or nylon membrane and so on. Usually the width of the test strip is between 3mm-6mm, in a specific embodiment, the width of the test strip is 4mm. the

In the following detailed description, reference texts accompanying the legends are a part hereof, and are presented by way of illustration of certain embodiments in which the invention may be practiced. We do not exclude that the present invention can implement other specific solutions and change the structure of the present invention without departing from the scope of use of the present invention. the

As shown in FIG. 1 , the common test strip 100 is composed of an outer sticker 110 , a sample pad 120 , a marking pad 130 and a detection pad 140 , an absorbent pad 150 and a bottom sheet 160 . Usually, when making test strips, the detection pad 140 is placed on the bottom sheet 160 first, and the marking pad 130 is connected above one end (upstream) of the detection pad, and the water-absorbing pad 150 is connected to the other end (downstream). The sample pad 120 is connected above the marker pad 130 . The top of the sample pad 120 is covered with the uppermost self-adhesive layer 110 , and the self-adhesive layer 110 is used to protect the sample pad 120 and the marker pad 130 located below it, and to mark some marks. The inner layer of the self-adhesive 110 has adhesiveness, and bonds the sample pad 120 , the marking pad 130 and the detection pad 140 located below it. In actual operation, the sample is added to the sample pad 120. For example, the sample pad 120 part of the test strip is put into the sample solution, and the sample is absorbed into the sample pad 120 and flows laterally along the test strip. The sample first passes through the sample solution. The marker pad 130 in contact with the sample pad 120 reacts accordingly, and then the analyte in the sample and the antibody reacted on the marker pad continue to flow forward together and reach the detection pad 140, where the control area 142 and the detection area 141 of the detection pad Reacts with related substances located on it, thus revealing the detection result. After the test strip has passed through the detection pad, the excess liquid continues to flow forward, reaches the downstream of the detection pad, and is absorbed by the water-absorbent pad 150 . Of course, the ordinary test strip 100 can also only be composed of the marker pad 130 and the detection pad 140 , and the sample can also be directly added to the marker pad, combined with the antibody on the marker pad, and then flow to the detection pad to complete the detection. the

In actual operation, ordinary test strips 100 may have insensitive reactions, especially for the test strips detected by the competition method, that is to say, the gradient between the negative and positive results of the test is poor, especially When the tested sample is positive, the result should theoretically have no detection line, but usually there will be a shallow detection line, and sometimes even a more obvious detection line will be displayed. This will cause trouble when the operator makes a wrong judgment or judges the result. the

After analysis, it is found that the detection line is generated because the antibody with the marker flows to the detection pad 140 and combines with the antigen fixed at the detection line T line 141. In theory, when the sample is positive, the labeled antibody It should all be combined with the positive substance in the sample (the positive substance in the sample is far greater than the amount of the labeled antibody, therefore, the labeled antibody should be fully combined), but in fact, the labeled antibody does not fully and fully combine with the positive substance. the

To solve this problem, it is necessary to make the labeled antibody on the labeling pad 130 fully or even fully combine with the positive substances in the sample. Therefore, an improved structure of the test strip 200, 300, 400 of the present invention can realize this function, that is, solve this problem. As shown in Figure 2, a novel test strip 200 also includes an outer sticker 210, a sample pad 220, a marker pad 230 and a detection pad 240, an absorbent pad 250 and the bottom sheet 260; the difference is, The sample pad 220 is extended and covered on the marking pad 230 to completely or partially cover the marking pad 230 . Figure 2 shows the full coverage case. Specifically, the bottom sheet 260 is provided with a detection pad 240, one end 241 of the detection pad is covered with a water-absorbing pad 250, and the other end 242 is connected or not connected to one end 231 of the marking pad, as shown in Figures 3 and 2 respectively. shown. Or, more preferably, the other end 242 of the detection pad is connected to the sample pad 220 . More specifically, the part of the marker pad 230 covered by the sample pad 220 is the effective working part of the marker pad 230 , that is, the sample pad 220 covers part or all of the marker pad 230 on which the marker is fixed. the

In a specific embodiment, a quantity of 100 labeled antibodies is processed and immobilized on the marking pad 230 of the improved test strip 200 of FIG. antigen. When the sample does not contain the positive substance that needs to be detected, after the sample is added to the extended sample pad 220, it flows along the sample pad 220 to the top of the marker pad 230, and after contact, it carries the labeled antibody and flows laterally downstream to reach The antigen on the detection pad 240 and the antigen on the detection line 243 is bound and retained, therefore, the detection result line 243 shows the color of the marker, for example, the purple red of the gold label. Of course, at this time, a control C line 244 showing whether the detection is valid or not will also appear on the detection pad. And when the sample contains a positive substance, usually the positive substance will be tens of times or even hundreds of times the amount of the labeled antibody fixed on the marker pad 230 of the test strip 200, we set the amount of a positive substance to be 1000, when the positive substance of 1000 flows to the bottom of the marker pad 230 along the extended sample pad 220, due to the limitation of the contact mode (through the contact between the bottom of the sample 220 and the part or all of the top of the marker 230), the marked Part of the antibody of the object is in contact with the positive substance, that is, 1/10 of the total 100 labeled antibodies, that is, 10 contacts and combines with 1000 positive substances, and then the subsequent sample with 1000 positive substances continues to flow over to the next part 10 of the labeled antibodies are contacted and combined, and so on. Finally, the fully combined labeled substance and the sample flow to the detection pad 240, because the labeled antibody is fully combined with the positive substance in the sample, and can no longer be connected to the detection line 243. antigen binding and thus cannot be retained. On the common traditional test strip 100, there is no extended sample pad or second sample pad, and the sample with positive substance on the sample pad 120 flows (i.e. rushes) from the sample pad to the end of the sample pad very quickly. On the lapped marker pad 130, the instant release of the number 100 on the marker pad 130 reacted with 1000 of the positive substance. Comparing the ratio of 10/1000 and 100/1000, it must be that the ratio of 10/1000 makes the response more fully. Therefore, the novel test strip 200 can make fewer labeled antibodies that have not had time to react be brought to the detection line 243 of the detection pad 240 and be intercepted. Therefore, the lines displayed at the detection line are weaker, or even none, thereby Make positive test results show better. the

In some embodiments, for the convenience of operation, the extended sample pad 220 can be divided into two sample pads: the first sample pad 222 and the second sample pad 221 . The first sample pad 222 is used to receive the sample; the second sample pad 221 is covered on the label pad 230, so that the detected substance in the sample can fully react with the labeled antibody. As shown in FIGS. 3 and 4 , one end of the first sample pad 222 is connected to and located on one end of the second sample pad 221 , and the second sample pad 221 completely covers the marker pad 230 . In some other preferred embodiments, there is a certain distance 270 between the labeling pad 230 and the detection pad 240, so that it can more fully ensure that the labeled antibody will not contact the detection antigen before contacting the sample, that is, the labeled antibody can be detected. Fully combined with the detected substance in the sample, as shown in Figure 4. the

More specifically, there is a part of the second sample pad 221 in the distance 270 between the marker pad 230 and the detection pad, and the two are communicated through the second sample pad 221 . As shown in Figure 4, one end of the second sample pad 221 is connected to the first sample pad 222, the other end 225 of the second sample pad is connected to the other end 242 of the detection pad, and the second sample pad 221 covers the marker pad 230 and pitch 270. the

In some preferred embodiments, the extended sample pad or the second sample pad also makes the outer layer of sticker 210 not in contact with the marking pad 230, so that the marking pad 230 will not be different in thickness due to the different bonding forces with the sticker 210. different. The sample pad 220 or 221 effectively separates the self-adhesive 210 and the marking pad 230, thereby avoiding the different forces on the two sides of the test strip 200, 300, 400 during the processing and molding process due to the adhesive bonding of the self-adhesive 210 The resulting asymmetry of the marker pad 230 . the

The material of the sample pad is to ensure that the sample carrying the gold standard can pass through as a selection principle. In a specific embodiment, the material of the sample pad 220, including the first sample pad 222 and the second sample pad 221, is polyester fiber membrane or nitric acid Cellulose membrane, glass fiber membrane or filter paper. In particular, in a specific embodiment, the first sample pad 222 is a glass fiber membrane; the second sample pad 221 is made of filter paper. the

Example

In order to explain more clearly how the present invention is implemented, limited experiments are now used for illustration. These descriptions are only limited examples under the essence of the claims of the present invention, and do not constitute limitations on the claims of the present invention. the

Example 1: Conventional test strip 100 vs. improved test strip 400 with two sample pads for detection of cannabis products (THC)

Materials: 6 urine collectors; 18 conventional test strips 100 produced by our company, selected from the same batch; 18 test strips 400 with two sample pads produced by our company, produced by the same batch; Cannabis standard: 25ng/ml

steps:

1. Configure 25ng/ml11-nor-Δ ⁹ -THC cannabis standard;

2. Add 20ml of 25ng/ml11-nor-Δ ⁹ -THC cannabis standard solution to 3 urine collectors respectively; then add negative to the other 3 urine collectors (containing about 20ml of urine) specimen;

3. Insert the sample areas of 3 conventional test strips 100 vertically into the same urine collector respectively, with the liquid level and the indicator line on the self-adhesive surface of the test strips as the boundary, wait for 10 seconds and then insert Take out the test strip, put it flat on the operating table, use the test strip reading standard color card to compare and read the depth of the test result line of the detection area on the test strip, and obtain the value. the

4. Repeat step 3, respectively insert the remaining conventional test strips 100 into the remaining 5 urine collectors, that is, insert every 3 into the same urine collector, conduct the test, and read the test results. the

5. Perform the same test on the test strip 400 with two sample pads according to steps 2, 3 and 4 above. the

6. The conventional detection test strip 100 is prepared according to the following method:

The reagent strip 100 shown in FIG. 1 is used to illustrate the components and manufacturing method of the reagent strip of the present invention used in this experiment. the

6.1. Treatment of nitrocellulose membranes . The detection sheet 140 is a nitrocellulose membrane (NC), and there are two lines on the nitrocellulose membrane, one is the detection line 141 , and the detection result control line 142 is located downstream of the detection line. Cannabis molecules linked with BSA are immobilized on the detection line 141 ; goat anti-rabbit IgG is immobilized on the detection result control line 142 . The fixed method can be processed automatically with an automatic spray film processing machine, wherein the concentration of the processing detection line is 0.6 mg/ml, and the dilution buffer is phosphate buffer solution (PBS); the goat anti-rabbit IgG is fixed on the detection result control line 142 Antibody; the concentration is 1.0 mg/ml, and the dilution buffer is phosphate buffered saline (PBS). Dry the treated nitrocellulose membrane in an oven at 45°C.

6.2 Handling of Gold Standard Pad 130 . The gold label pad is a polyester film, and the hemp antibody labeled with colloidal gold particles is processed on the polyester film. The OD value of the treatment solution was 60, and the dilution solution was 1 times PBS buffer solution, which also contained 1% BSA. Colloidal gold-labeled rabbit IgG antibody was also processed on the labeling sheet. Dry the processed marker sheet in an oven at 37°C.

6.3 Handling of the sample pad 120 . The sample pad is a glass cellulose membrane, and the solutions treated on the membrane are: Tween20 (1%); Cholic Acid (0.1%); Tris (0.1M). Put the processed sample receiving piece in a 37°C oven to dry.

6.4. Assembly of the reagent strip 100 . Assemble the processed parts in the order shown in Figure 1, so that the sample pad is located upstream of the gold standard pad, the gold standard pad is located between the detection pad and the sample pad, and an absorbent pad is placed downstream of the detection pad. These components are placed on a non-absorbent support sheet. The top layer of the test strip is covered with self-adhesive, and at one end of the test strip, the self-adhesive covers one end of the sample pad, gold standard pad and detection pad; at the other end of the test strip, the self-adhesive covers the absorbent pad and the other end of the detection pad covered.

7. Prepare the test strip 400 with double-sample pads as follows:

7.1 The nitrocellulose membrane 240, the gold standard pad 230, and the first sample pad 222 are treated in the same way as the conventional test strip 100, and the second sample pad 221 uses untreated filter paper.

7.2 Assembly of test strip 400 . The processed parts are assembled according to the order shown in Figure 4, so that the first sample pad 222 is located upstream of the second sample pad 221, and one end of the two sample pads is connected, and the gold standard pad 230 is located on the first sample pad 222, and is located directly below the second sample pad 221, covered by the second sample pad 221, wherein the NC film 240 is located downstream of the gold standard pad 230, and there is a certain distance between the gold standard pad and the NC film 270 , the second sample pad 221 is located within this distance and the other end 225 of the second sample pad is connected to one end 242 of the NC membrane, and a water-absorbing pad 250 is placed downstream of the NC membrane 240 . These components are placed on a non-absorbent support sheet 260 . Cover the uppermost layer of the test strip 400 with a self-adhesive 210, and at one end of the test strip 400, the self-adhesive 210 covers the first and second sample pads 222, 221, the gold standard pad 230 and one end 242 of the NC film; At the other end of the test strip 400 , the self-adhesive 210 covers the absorbent pad 250 and the other end 241 of the NC film.

explain:

Standard color card: the color comparison range of the standard color card is between 0-10, that is, G1-G10, and the range that can display the result line is between 7-10, that is, when the line color of the test result falls between 7- A range of 10 indicates a negative test result. When the line is not within this range, the test result is positive or the test result is incorrect;

The test results are as follows

Table 1: Test results of ordinary test strip 100

Table 2: Test results for test strip 400 with dual sample pads

Analysis and comparison of test results:

Compared with Table 1 in Table 2, the positive samples decreased from G4.5-G5 to G3.5; the negative samples changed from G8 to G8-G8.5. Therefore, from the above results, the test result of the improved test strip is larger than that of the conventional test strip, from G4.5-G8 to G3.5-G8.5. In this way, the sensitivity of the test is relatively improved, making it easier for the operator to judge whether the test result is negative or positive. the

Example 2: Testing Multiple Products Using Conventional Test Strip 100 and Improved Test Strip 400 with Two Sample Pads

1. The operation steps are basically the same as in Example 1, except that the positive samples of each product are prepared separately, and the specific concentrations are shown in the list. the

2. The production of the test strip is also the same as in Example 1, wherein the antibody immobilized on the detection line of the NC membrane and the labeled antibody immobilized on the marker pad correspond to the product to be detected. That is, the cannabis molecules, AMP, COC, MET, MOP, BZO, PCP, OXY, and BUP are immobilized on the detection line 141 or 243 and the marker pad 130 or 230 respectively. the

3. Experimental results:

Remarks: The code of conventional test strips is 1; the code of improved test strips is 2

Analysis and comparison of test results:

The effect of the improved test strip is more significant than that of products with low concentration values (that is, high sensitivity requirements). Therefore, the improved test strip is especially suitable for the detection of products with high sensitivity requirements, such as marijuana, buprenorphine, phencyclidine, etc. the

Claims (12)

1. detect a test strips for sample, comprise, label pad and detecting pad, detecting pad is positioned at the downstream of label pad, it is characterized in that, this test strips also comprises sample pad, and described sample pad is by all or part of for label pad covering.

2. test strips according to claim 1, is characterized in that, sample pad is connected with detecting pad.

3. test strips according to claim 2, is characterized in that, described label pad can be connected with detecting pad.

4. test strips according to claim 2, is characterized in that, has certain spacing between label pad and detecting pad.

5. test strips according to claim 4, is characterized in that, sample pad separates label pad and detecting pad.

6. according to the test strips one of claim 1-5 Suo Shu, it is characterized in that, sample pad is divided into two parts: the first sample pad and the second sample pad.

7. test strips according to claim 6, is characterized in that, the first sample pad is connected with the second sample pad; First sample pad and the second sample pad tie point are positioned at the upstream of label pad.

8. test strips according to claim 7, is characterized in that, the second sample pad overlay marks pad.

9. test strips according to claim 8, is characterized in that, the second sample pad is connected with detecting pad.

10. according to the test strips one of claim 1-9 Suo Shu, it is characterized in that, described test strips also comprises outer adhesive sticker.

11. test strips according to claim 10, is characterized in that, outer adhesive sticker covers detecting pad and is positioned in the sample pad above label pad; Sample pad separates outer adhesive sticker and label pad.

12. test strips according to claim 1, is characterized in that, the material of described sample pad is dacron film, glass fibre membrane or filter paper.