JP2532788C - - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to immunoassays for detecting the presence of an immunoreactive analyte in an aqueous sample, particularly in the form of a self-contained, single-step solid phase strip. The present invention relates to an assay device and method. Assays based on the prior art, especially reactions between immunoreactive substances, have been used, for example, in clinical medicine, forensic medicine, environmental testing, food quality testing, drug testing and other relevant techniques for detecting the presence of immunoreactive analytes in samples. Widely used in fields such as areas. The development of non-radioactive standards or ayas has facilitated the use of immunoassay diagnostics in laboratory facilities, clinics and even remote locations such as the user's home. In clinics, immunological methods can be performed while the patient is in the clinic, thus providing a quick and simple assay that can be screened and treated without delay during a single consultation. Useful in Without such a simple assay, a physician would collect samples from a patient during the first visit, analyze the samples in a clinic lab, and return the results to the physician at a later time. It was often necessary. On the other hand, the patient had to be returned home and had a second re-examination with the physician to receive the appropriate treatment and / or medication. Obviously, such an assay delay is inefficient and inappropriate, and in some cases life threatening. Home testing has become desirable for patients to facilitate testing in privacy at home. The results of such a test may, for example, indicate whether a visit to a physician is necessary. Examples of useful "market" tests in the "home" include pregnancy, ovulation, streptococcal infections and e.g.
Includes testing for other infections that can be detected by analyzing blood or other suitable samples. For remote testing, there are at least three requirements for a practical assay procedure, given the appropriate sensitivity and specificity that can be achieved. One of these desirable factors is the speed at which the test must be performed in an acceptable short time, the shorter the better. Stability is also a desirable feature in that the assay element should be stable without long periods of freezing or requiring special treatment. Finally, from a commercial point of view, the test is convenient to use, as simple as possible, requires minimal instrumentation, or eliminates any instrumentation and eliminates mistakes and poor performance that give inaccurate results. desirable. One of the difficulties encountered in the development of inspection equipment for remote inspection is a practical, pre-packaged, disposable device to facilitate an efficient, relatively inexpensive, and undeniable inspection method. It is to provide. This means that it is inexpensive to manufacture, has a shelf life suitable for the life of the device, is protected from contamination during handling, can be used simply and conveniently when it is appropriate to use it, Needless to say, a person who needs a device that can be conveniently and safely used. The device described in U.S. Pat. No. 4,868,108 addresses these problematic ones. However, this device incorporates tests that utilize enzyme colorants that are often subject to substrate intervening and are often unstable, which adversely affects shelf life. No. 4,868,108, commonly assigned with the present invention, the entire disclosure of which is specifically incorporated herein by reference. Another known device is the British patent application G.A. B2204398A. This device uses colloidal gold or colored particles called "direct" labels. However, in this device, the unlabeled reaction components are permanently fixed in the observation zone. This affects the efficiency of the analyte detection mechanism. These prior art devices have excellent shelf-life characteristics and are simple, inexpensive, efficient, undeniable, pre-packaged, and do not satisfy the demands for single-stage devices. SUMMARY OF THE INVENTION The present invention provides a simplified, inexpensive, efficient, undeniable, prepackaged, one-stage device with good shelf life characteristics. Furthermore, according to the invention, the detection reaction takes place in the liquid phase with all components in a free-running state. For this reason, the efficiency and speed of the present invention are improved. Further according to the present invention there is provided a method for detecting an immunoreactive analyte in an aqueous sample. In one aspect of the present invention, there is provided a water-dispersible labeling component comprising a binding product (a first particle) of a first immunoreactive substance and a detectable species, wherein the captureable species and the second immunological substance are provided. Providing a water-dispersible trappable component consisting of a binding product (second particle) with a biologically reactive substance, comprising a trappable species localized in a detection zone on a porous carrier material. Providing a capture component comprising a capture material capable of interacting with the reaction product to capture and collect the product in the detection zone, providing a label and a captureable component, wherein the analyte is a liquid containing the sample and said component. Contacting with an aqueous solution of the sample to be analyzed to form a reaction mixture, wherein said first and second substances are the same or different and can be directly or indirectly bound as an intervening function of said analyte; Therefore, captureable products Forming a dispersed, diffusible reaction product containing the reactive component and contacting the liquid reaction mixture with the capture component in the detection zone so that the reaction product containing the captureable component interacts with the capture material to provide a detection zone. Collected at
Detecting the analyte in the sample by assessing the presence of a detectable species in the reaction product immobilized in the zone. According to a particularly preferred aspect of the invention, the labeling component and the trappable element are each initially dry, reconstitutable, water dispersible and diffusible. According to this aspect of the invention, the components are reconstituted when the same components are contacted with an aqueous solution containing the sample to be analyzed for the analyte. According to another particularly preferred aspect of the invention, the labeling component and the trappable component are each contained in a porous carrier material, wherein the liquid reaction mixture diffuses, moves through the porous carrier material and reacts in the detection zone. The object is brought into contact with the capture element. In still another aspect of the present invention, the labeling component and the captureable component are each
Contained in a zone in the porous carrier material, the liquid reaction mixture diffuses and travels through the porous carrier material to the detection zone, where the reactants contact the capture component in the detection zone. In yet another aspect of the invention, the labeling component is included in a first zone of the elongated strip of porous carrier material and the trappable component is included in a second zone of the strip of porous carrier material. The detection zone is also in a strip of porous carrier material. In a preferred aspect of the present invention, the first and second zones can be separated in the longitudinal direction of the strip. Further, the detection zone may be longitudinally spaced from one end of the strip, and the first and second zones may be located between the end of the strip and the detection zone. According to a particularly preferred form of the invention, the step of contacting the mixture with the capture component is achieved by diffusing and moving the mixture along the strip from the first and second zones to the detection zone. it can. Further, reconstituting the components may include providing a liquid sample to one end of the strip to cause the sample to diffuse along the strip to first and second zones. The invention also provides an apparatus for performing the process of measuring and detecting an immunoreactive analyte in an aqueous sample. The device of the present invention includes a water-dispersible labeling component comprising a binding product of a first immunoreactive substance and a detectable species. The device also includes a water-dispersible trappable component comprising a binding product of the trappable species and the second immunoreactive substance.
The first and second substances can be the same or different and can be directly or indirectly bound as a function of analyte intervention, thus forming a water-dispersible, diffusible reactant containing trappable components. Things are fine. The device also includes a capture component localized in a detection zone of the porous carrier material, wherein the capture component is capable of interacting with a reactant containing the captureable species, thereby capturing the product in the detection zone, and Contains capture material that can be collected. In a preferred form of the invention, the device may comprise an elongated strip of a porous carrier material. In this aspect of the invention, the labeling component is contained in a first zone of the strip of porous carrier material and the trappable component is contained in a second zone of the porous carrier material. The detection zone is also located on a strip of porous carrier material. In this aspect of the invention, the first and second zones are separated in the longitudinal direction of the strip, and the detection zones are first and second zones.
Is located between the end of the strip and the detection zone which is longitudinally spaced from the strip and is longitudinally separable from one end of the strip. Ideally, the device would include a core member in intimate contact with the element at one end.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of an assay device according to the present invention, and FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION An apparatus 10 for measuring and detecting an immunoreactive analyte in a liquid sample and implementing the principles and concepts of the present invention is shown in FIG. The device 10 shows a basic element 12 of a porous, preferably microporous, carrier material. As shown in FIG. 1, the basic element 12 is in the form of an elongated strip of a porous carrier material. The porous carrier material on which the strip 12 is formed should have a pore size of about 25 microns or less, and typically the pore size may be between about 5 and about 10 microns. The strip 12 may be formed from a water-absorbing material such as, for example, nylon or cellulose material. A particularly useful material according to the invention is Ahlstrom No. A commercially available material known as 345 paper. This material is smooth, white and composed of 100% cellulose. A preferred material has a basis weight of about 158 g / m ² , a thickness of about 0.7 mm, and a weight of about 80 mm / m ^2.
It has a capillary rising characteristic for an aqueous solution for a minute. Of course, various types of materials can be used depending on the desired properties of the particular assay procedure. For example, a watchman (W
Commercial materials known as hatman 903 and Wattman 31ET paper have been found to be useful according to the invention. A core member 14 is attached to the strip 16 at one end 16 of the strip, as can be seen from FIGS. The wick 14 may be made of either an aligned or unaligned (biaxial) configuration of the fibers in the form of American Filtrona (A)
may be formed from a bonded cellulose acetate fiber material commercially available from American Filtrona). The core material 14 is divided into separate rectangular pieces 14a, 14b and then pressed tightly against both sides of the
And the strip 12 may be formed from an elongated block of material that is tight and in communication contact by capillary action. For this purpose, the individual pieces 14a and 14b can be held tightly together and against the face of the strip 12 by means of a pair of bands 34 and 36. These bands 34, 36 may be devices commercially available as BARLOK cable ties (Denison-Denison part number 08429, military standard 3367-4-9). Referring to FIGS. 1 and 2, it should be pointed out that the various methods are not necessarily to scale. In a useful form of the invention, the strip 12 may be, for example, 150 mm long and 9.5 mm wide, for example. The thickness of the strip 12 ranges from 0.5 to 1.0 mm, and is preferably about 0.7 mm. However,
The particular dimensions of the strip are not critical, and the various dimensions may be modified as necessary to achieve the desired results in speed and / or color strength to represent a reliable test result. The core member 14 may initially have a length of about 51 mm, a width (w) of about 10.5 mm, and a thickness (t) of about 12.5 mm. The elongate core 14 is preferably located to extend the length of the element 12, as shown in FIG. Apparatus 10 includes a series of zones 18, 20 and 22 located on strip 12. Zone 20 contains a dry, reconstitutable, water-dispersible, diffusible labeling component consisting of a first immunoreactive substance. Preferably, the labeling component in zone 20 comprises the binding product of the first immunoreactive substance and the detectable species. Zone 18
A dry, reconstitutable, water-dispersible, diffusible capture component comprising a second immunoreactive material is included. The capture component is localized in the detection zone 22 and comprises a capture material that can interact with the captureable component and capture and collect the captureable component in the detection zone. In this way, the capture material can also capture and collect the captureable component and what is bound thereto. In the useful form of the invention shown in FIGS. 1 and 2, zones 18 and 2
0 are spaced apart in the longitudinal direction of the strip 12. However, it should be appreciated that these zones may overlap. Further, the relative positions of the zones 18 and 20 may be reversed. Referring to FIG. 1, the detection zone 22 is also longitudinally spaced from the end 16 of the strip 12, and the zones 18 and 20 are longitudinally spaced from the end of the strip 16 and the zone 22. And is located between. The core member 14 is arranged to extend along the element 12 from the end 16 toward the zones 18, 20. The wick 14 terminates in a spaced relationship to the zone 18 as shown, with the end 14a of the wick 14 positioned about 2.5 mm from the zone 18 to provide a space 24 therebetween. Further, a space 26 is provided between zones 18 and 20 and a space 28 is provided between zones 20 and 22. Finally, a space 30 extends from the zone 22 to the end 32 of the strip 12. Element 12
The core 14 has a preferred dimension of about 51 mm when measured along the length of
Has a preferred dimension of about 20 mm, the space 26 has a preferred dimension of about 2.5 mm, the zone 28 has a preferred dimension of about 2.5 mm, and the zone 22 has a preferred dimension of about 2.6 mm. With preferred dimensions, space 30 has a preferred dimension of about 71.9 mm. The immunoreactive substance of the labeling component in zone 20 and the immunoreactive substance of the trappable component contained in zone 18 can be the same or different, and the only requirement of the present invention is that Must be capable of binding directly or indirectly as an intervening function of a chemical reaction analyte to form a water-dispersible and diffusible reaction product containing the captureable component and the labeling component. According to one preferred form of the invention, the immunoreactive substances can each bind the analyte to form a sandwich. In this regard, each of the agents may be a monoclonal antibody capable of immunologically binding the target antigen analyte. Alternatively, an appropriately pure polyclonal antibody of appropriate specificity can be employed.
Such antibodies bind each different site in the antibody. In another aspect of the invention, the immunoreactive substances can bind to each other. That is, one of the substances may be an antigen and the other an antibody thereto. The immunoreactive substance of the labeling component may be an antigen, and in this form of the invention, the assay procedure may be determined by a competitive inhibition procedure for detecting unknown antigenic analytes in the sample. As mentioned above, the labeling component comprises the binding product of the immunoreactive substance and the detectable species. The detectable species may be a metal-containing particle. From about 25 to about 1000 約
The antibody or antigen may be coated on the metal colloid particles having a particle size in the range described above and used according to the present invention. Such coated particles strongly color orange, red or purple depending on the particle size. However, the present invention is broadly useful with any type of label capable of binding to the immunoreactive substance, independent of the particular properties or properties of the label or immunoreactive substance. The captureable components contained in zone 18 also consist of immunoreactive substances. Further, the captureable component comprises a captureable species, such that the captureable component comprises a combined product of the captureable species and the immunoreactive substance. The capture component localized in the detection zone 22 comprises a capture material that interacts with the captureable component to allow a reaction product containing the captureable component to be captured and collected in the detection zone. Is preferred. The capture material is strip 12
Can be directly bonded to the cellulosic material in which is formed. However, in a preferred form of the invention, the capture material can bind to solid particles having dimensions and properties that can be localized by being deposited in the pores of the porous carrier material in the detection zone. In this aspect of the invention, the solid particles may be comprised of any of a number of known water-dispersible particles. Solid particles useful in connection with the present invention include, for example, particles of latex or other support materials such as, for example, silica, agarose, glass, polyacrylamide, polymethyl methacrylate, carboxylate modified latex and Sepharose. The particles vary in size from about 0.2 microns to about 10 microns. Particularly preferred materials for use in connection with the present invention are assigned with the present invention, filed April 4, 1988, the entire disclosure of which is hereby specifically incorporated by reference, Consists of 0.99 micron carboxylate modified latex particles (Polyscience) as described in pending U.S. Patent Application No. 177,114. In a particularly preferred form of the present invention, device 10 may be used to detect pregnancy. For this purpose, the 2B2 antibody can be used. The 2B2 antibody can bind to biotin, the latter acting as a trappable species. To biotinylate the 2B2 antibody, 50 mg of biotin-X-NHS is first degraded to 5 ml of DMSO. The solution containing the antibody contained 13.32 ml of 1 M Na ₂ CO ₃ and 80 ml of 0.15 M Na
Cl and then 833.35 mg of dialyzed 2B2 antibody and 29.3 ml of DMS.
It is adjusted by adding O to the mixture. Then, biotin and DMSO
Is added to the antibody solution and the resulting mixture is allowed to react for about 2 hours at room temperature. After incubation, the complex thus formed of 2B2 / biotin is dialyzed against a 0.15 M NaCl / 0.05% NaH ₃ solution at 4 ° C. for 48 hours. Next, the complex was made up of 12.11 g / l Tris base, 100 g / l MALTRIN 365 (
Grain Processing Corp.), 3 g / l EDTA disodium salt,
By adding to a volume of buffer (ph 8.0: 0.05) containing 0.3 ml / l IGEPAL CA 720 (GAF Campany), 0.1 g / l thimerosal, the protein concentration was reduced. It is about 0.5 g / l. The resulting solution is sprayed on the strip in a 2 μl zone 18 and dried. The functions and component properties of the various components of the buffer are described in detail in co-pending and pending application Ser. No. 07 / 344,575, which is hereby incorporated by reference for its entire disclosure. Has been described. In a preferred form of the invention, the labeling component in zone 20 ideally comprises the binding product of the first immunoreactive substance and the detectable species. For pregnancy assays, the preferred immunological reactant is the 2G9 antibody and the preferred detectable species is colloidal gold particles. Gold colloid particles preferably have a diameter of about 30 nm (Gee, Furensu of Necha -G.Frens, Nature 241,20-22 (1
973)). The antibody-coated colloidal gold particles can make up the final product consisting of colloidal gold-labeled probe particles that can be used as a labeling component in a preferred form of the invention. The colloidal gold labeled probe particles contain about 10.2 mg of 2G9 antibody for each 1000 OD 533 rm unit of 30 nm gold colloidal particles. The colloidal gold particles coated with the antibody contained 45.45 g / l bovine serum albumin (BSA), 0.667 g / l sodium azide, 9.09 ml / liter.
TRITON X-100, 8.69 g / l Tris base and 253.64 g / l M
ALTRIN 365, 0.215 ml of IGEPAL CA720 and 0.07
It is contained in a solution containing 18 g / l of thimerosal and 8 mg / l of the 2G9 antibody coated to colloidal gold particles at 785.45 OD 533 nm. Then 5
Dispense 0 μl of this solution to cover zone 20 of device 12 and allow the solution to air dry. TRITON X-100 is Rohm and Haas Kampani.
Octylphenoxypolyethoxyethanol (o
It is a nonionic surfactant of ctyl phenoxy-polyethoxy ethanol). The capture component in zone 22 may be composed of, for example, an avidin material that is streptavidin complexed with solid latex particles. Next, streptavidin latex particles may be deposited and localized in the pores of the porous carrier material of the strip in zone 22. To prepare streptavidin latex particles, 28
0 mg of streptavidin is dissolved in 560 ml of 0.15 M NaCl. In a separate container, 1050 ml of 0.36 M NaCl contains 15.47 g of 0.99 μ carboxylate modified latex (Polysciences).
Added to 0 ml latex suspension. Sufficient pure water is added to bring the total volume of the latex containing the suspension to about 2 liters. To activate the latex, 10.5 g of carbodiim in 105 ml of water
ide) is added to the latex suspension, the latter being allowed to react for about 10 minutes.
The carbodiimide-activated latex is then collected in a centrifuge and resuspended in about 1540 ml of a 0.14 M NaCl solution. The streptavidin solution prepared as described above is mixed with the activated latex solution, and the mixture is stirred for 10 to 20 hours. After the reaction was completed, 210 ml of a 1 M glycine solution was added to the streptavidin latex suspension and the suspension was again added to about 1
Stir for hours. The mixture is centrifuged and the supernatant is aspirated. The streptavidin latex complex is then washed with a convenient saline solution and centrifuged again. The product is resuspended in a sufficient amount of an aqueous solution containing 300 g / l of MALTRIN 365 and 0.5 g / l of sodium, azide, to give about 73 g / l.
Provide a final suspension containing 5 g streptavidin latex. next,
20 μl of the above suspension containing about 1.47 mg of streptavidin latex
Is supplied to the zone 22. The suspension is supplied to zone 22, while a vacuum of 19 inches (482.6 millimeters of water) is applied to the opposite side of strip 12, preventing streptavidin latex from spreading across the zone, And allow the latex particles to completely penetrate the pores of the strip 12 in the zone 22. Prior to the application of the core element 14 to the strip 12, the core is made up of 12.1 g / l Tris base, 100 g / l MALTRIN 365, 3 g / l disodium EDTA, and 0.3 ml / l IGEPALCA 720. It is preferably treated with a solution containing 0.1 g / l thimerosal, 10 g / l BSA and 0.5 ml / l TRITON X-100. The treatment involves penetrating the wick 14 into the solution and drying the solution. Such treatment has been found to prevent non-specific absorption. In use, the test solution may simply be supplied to the end of the device 10. For pregnancy tests,
The wick 14 may be exposed to the liquid sample by placing it directly in the first day morning urine flow. Given that the subject of the test is pregnancy, such urine may be immunologically reactive to some degree in human germinal stimulating hormone (hCG), ie, immunologically reactive with the 2B2 antibody. There is a hormonal analyte that has one first site and another site that is particularly immunologically reactive to the 2G9 antibody. Since the urine is absorbed by the absorbing action of the core member 14 and the core member is in close contact with the surface of the element 12, the holes of the element 12 allow the urine to be bound by capillary action in the direction from the end 16 to the end 32. It is made to move along the piece element 12. As the urine sequentially traverses zones 18 and 20 due to the capillary action of the pores of element 12, the urine comes into contact with the dried labeling component and the trappable component, reconstituting these components to form the urine and its components. A liquid reaction mixture is formed containing the components dispersed therein. Since the captureable component 2B2 antibody from zone 18 is immunoreactive with specific sites on the hCG molecule and the labeled component 2G9 antibody from zone 20 is immunoreactive with different specific sites on the hCG molecule, A reaction product consisting of a sandwich of the labeled 2G9 component and the hCG and the biotinylated 2B2 component is formed. Notably, the reaction to form the reaction product is performed in a liquid system in which the reactants are all free to move. Thus, the reaction is efficient and provides reliable results with minimal amounts of reactants and low levels of analyte. Urine diffusing the reaction product continues to diffuse and travel along the strip 12 by capillary action until the mixture encounters streptavidin bound to the latex granules localized in zone 22. . Capture and collect the reaction product in zone 22 by reaction between streptavidin bound to latex particles and biotin bound to 2B2 antibody in the reaction product containing colloidal gold label bound to 2G9 antibody I do. Thus, the localized capture component in zone 22 includes avidin as a capture substance that can interact with a reaction product that includes a captureable component consisting of biotin as a captureable species. Avidin interacts with biotin to capture and collect the reaction product in zone 22, where the gold label is concentrated and becomes a visible detectable zone. Gold is collected and concentrated in zone 22 to provide an immediately visible color that can be visually detected and indicate a reliable result. If the urine sample does not contain hCG, the gold-labeled 2CG antibody simply diffuses through zone 22 and spreads out along space 30, where the individual gold particles diffuse and see a distinct coloration Can not do. Although the biotinilate 2B2 antibody is always collected and concentrated in zone 22, there is no way to collect the gold-labeled 2G9 antibody at that location without the intervention of hCG. In the specific example described above, streptavidin is employed as the capture substance;
Biotin has been employed as a catchable species. The reason for choosing these materials is that
Because they interact quickly and firmly to provide a reliable capture and collection function. Other avidin materials may be used. Further, the invention is not limited to these particular materials, but may employ other alternative interacting materials.
For example, antibodies can be raised against fluorescein thiocyanate, and the binding action between those antibodies and fluorescein thiocyanate can be used to capture and collect the reaction products. Thus, the 2B2 antibody can be bound to fluorescein thiocyanate to provide a captureable component, and the antibody to fluorescein thiocyanate can be bound to solid phase particles to provide a localizable capture component. . Other potential materials are known in the art, but the only limitation in this regard is that the captureable species must be capable of binding to a suitable immunoreactive substance and providing a captureable component; and The requirement is that the capture material can be localized in the appropriate detection zone.

Claims (1)

[Claims] 1. In an immunoassay of an aqueous sample for measuring an immunoreactive analyte, (1) an elongated strip element having a pair of opposite ends through which the aqueous dispersion is diffused by capillary action. A strip element formed from a water-absorbing carrier material having a porous structure capable of forming, (2) a capture component localized in a detection zone of the strip element, specifically binding to a trappable species. Providing an immunoassay device comprising a capture species, wherein the capture zone comprises a capture component, wherein the capture zone is spaced from at least one of the ends of the strip element. An aqueous sample to be dispersed and (b) a dispersed first product comprising a first binding product of a first immunoreactive substance and a metal-containing particle that is a detectable label.
An aqueous dispersion comprising: a first batch of particles of the second, and (c) a second batch of dispersed second particles consisting of a second binding product of the second immunoreactive substance and the trappable species. A system wherein the first and second immunoreactive substances are the same or different, and are either relative to the analyte or as a function of the intervening or quantity of the analyte in the aqueous dispersion system. Forming an aqueous dispersion that is capable of binding specifically, either antagonistically or non-antagonistically, thereby forming a composite reaction product consisting of both the first and second particles; Along the one-piece element, diffusing through the water-absorbing material to the detection zone to contact the composite reaction product with the capture component to passivate and concentrate the composite reaction product in the detection zone, where One of the species is biotin The other species consists of avidin, the specific binding function described in (2) above comprises the formation of a biotin-avidin conjugate, and the presence or absence of an immunoreactive analyte in the aqueous sample. Assessing the detection zone for the presence of a marker detectable as an indicator. 2. The method according to claim 1, wherein the aqueous sample is urine. 3. The method of claim 1, wherein the first binding product is prepared by directly binding a first immunoreactive substance to a metal-containing particle. 4. The method according to claim 1, wherein the metal-containing particles are metal colloid particles. 5. The method of claim 4, wherein said metal colloid particles have a particle size in the range of about 25 to about 1000 Angstroms. 6. The method according to claim 4, wherein the metal colloid particles are gold colloid particles. 7. The method of claim 1 wherein said captureable species comprises biotin and said capture species comprises avidin. 8. The capture component comprises a third combined product of a third particle and the capture species;
The method according to claim 1, wherein the third particles are deposited in the pores of the passivated carrier material in the detection zone and are therefore passivated. 9. 9. The method of claim 8, wherein said captureable species comprises biotin, said capture species comprises avidin, and said specific binding function comprises forming a biotin-avidin conjugate. . Ten. Both the first and second particles are initially included in the water-absorbing carrier in a dry, reconstitutable, and water-dispersible form, and the aqueous dispersion is dried and reconstitutable. The method of claim 1, wherein the method is formed by contacting particles with the aqueous sample. 11． The contact between the aqueous sample and the dried, reconstitutable particles may be such that the strip element is first contacted with the aqueous sample, and then the sample is passed through the water-absorbent carrier material, and dried and contacted with the reconstitutable particles. The method according to claim 10, wherein the method is adapted to perform by diffusion. 12． The dry, reconstitutable, water-dispersible particles are first included in one or more contact zones of a water-absorbing support material, and the aqueous dispersion diffuses the aqueous sample through the contact zone. The method of claim 11, wherein the method is formed. 13. Wherein a first batch of the particles is included in a first contact zone of the water-absorbing material, and a second batch of the particles is included in a second contact zone of the water-absorbing material. 13. The method of claim 12, wherein the method comprises: 14. 14. The method of claim 13 wherein said step of contacting said strip element with an aqueous sample comprises immersing said one end of said elementary element in an aqueous sample.
The method described in the section. 15． 14. The method of claim 13, wherein said first and second contact zones are spaced longitudinally of said strip element. 16． The method of claim 1, wherein the first and second contact zones are disposed between the one end of the strip and the detection zone in a longitudinally spaced relationship to the detection zone. 14. The method of claim 13, wherein the method comprises: 17． 14. The method according to claim 13, wherein the first binding product is prepared by binding a first immunoreactive substance directly to a metal-containing particle. 18． 14. The method according to claim 13, wherein the metal-containing particles are metal colloid particles. 19. 19. The method of claim 18, wherein said metal colloid particles have a particle size in the range of about 25 to about 1000 Angstroms. 20. 19. The method according to claim 18, wherein the metal colloid particles are gold colloid particles. twenty one. 14. The method according to claim 13, wherein said captureable species comprises biotin and said capture species comprises avidin. twenty two. The capture component comprises a third bond product of a third particle and the capture species, wherein the third particle is deposited in the pores of the water-absorbent carrier material in the detection zone and is therefore passivated. 14. The method according to claim 13, wherein: twenty three. Wherein the captureable species comprises biotin, the capture species comprises avidin,
23. The method of claim 22, wherein said specific binding function comprises forming a biotin-avidin conjugate. twenty four. 14. The method of claim 13, wherein the first and second immunoreactive substances each specifically bind to a different site of the analyte to form a sandwich. twenty five. 25. The method according to claim 24, wherein said first and second immunoreactive substances are each an antibody, and said analyte is an antigen specifically bound by both antibodies. 26. 14. The method according to claim 13, wherein the first and second immunoreactive substances specifically bind to each other. 27. 27. The method of claim 26, wherein one of said immunoreactive substances is an antibody and the other is an antigen specifically bound by said antibody. 28. 27. The method according to claim 26, wherein the first immunoreactive substance is an antibody and the second immunoreactive substance is an antigen specifically bound by the antibody. 29. A kit of materials for the immunoassay of an aqueous sample for measuring an immunoreactive analyte, comprising: (1) an elongated strip element having a pair of opposite ends through which an aqueous distribution system is passed. A strip element formed from a water-absorbing carrier material having a porous structure that can be diffused by capillary action; and (2) a capture species that is localized in the detection zone of the basic element and can specifically bind to the trappable species. An immunoassay device comprising: a capture component wherein the detection zone comprises a capture component spaced from at least one of the ends of the strip element; and a first immunoreactive substance and a detectable label. A first batch of dry, reconstitutable, water-dispersible first particles comprising a first binding product with certain metal-containing particles; a second batch of immunoreactive material and said trappable species; Drying and re-consisting of the second binding product of A second batch of configurable, water-dispersible second particles, wherein the first and second particles of the first and second batches are dispersed with the sample by contacting the aqueous sample. Forming an aqueous dispersion containing the first and second granules, wherein the first and second immunoreactive substances are the same or different, and the presence or amount of the analyte in the aqueous dispersion is reduced. As a function, the analyte or the analyte can be specifically or antagonistically or non-antagonistically bound to form a complex reaction product consisting of both the first and second particles, and the water-absorbing carrier material is The aqueous dispersion diffuses along the strip elements and through the water-absorbing material to contact the composite reaction product with the localized capture components in the detection zone and passivate the composite reaction product in the detection zone. Where one of the species is biotin The other species consists of avidin, the specific binding function according to (2) above consists of the formation of a biotin-avidin conjugate, and by concentration, the detection zone is an immunoreactive analyte in the aqueous sample. A kit that can be evaluated for the presence of a detectable label as an indicator of the presence or amount of the kit. 30. 30. The kit according to claim 29, wherein the aqueous sample is urine. 31. 30. The kit according to claim 29, wherein said first and second particles are contained in a water-absorbing carrier material. 32. 32. The kit of claim 31, wherein the first and second particles are contained in one or more contact zones of the water absorbing material. 33. A first batch of the particles is included in a first contact zone of the water absorbent material, and a second batch of the particles is included in a second contact zone of the water absorbent material. 33. The kit according to claim 32. 34. 34. The kit of claim 33, wherein said first and second contact zones are spaced apart in a longitudinal direction of said strip. 35. 9. The method according to claim 8, wherein the first and second contact zones are disposed between the one end of the strip element and the detection zone in a longitudinally spaced relationship with the detection zone. 34. The kit according to paragraph 33. 36. The method of claim 1 wherein the first and second contact zones are disposed between the one end of the strip element and the detection zone in a longitudinally spaced relationship to the detection zone. The kit of claim 34. 37. 37. The kit of claim 36, wherein the first binding product is prepared by directly binding a first immunoreactive substance to a metal-containing particle. 38. 37. The kit according to claim 36, wherein the metal-containing particles are metal colloid particles. 39. 39. The kit of claim 38, wherein said metal colloid particles have a particle size ranging from about 25 to about 1000 Angstroms. 40. The kit according to claim 38, wherein said particles are colloidal gold particles. 41. 37. The kit of claim 36, wherein said captureable species comprises biotin and said capture species comprises avidin. 42. The trapping component comprises a third binding product of a third particle and the trapping species, wherein the third particle is deposited in the pores of the water-absorbing carrier material in the detection zone and is therefore passivated. 37. The kit according to claim 36, wherein: 43. Wherein the captureable species comprises biotin, the capture species comprises avidin,
43. The kit of claim 42, wherein said specifically binding function comprises forming a biotin-avidin conjugate. 44. 4. The method of claim 3, wherein the first and second immunoreactive substances specifically bind to different sites of the analyte to form a sandwich.
Item 7. The kit according to Item 6. 45. 4. The method according to claim 3, wherein the first and second immunoreactive substances are each an antibody, and the analyte is an antigen specifically bound by both antibodies.
Item 7. The kit according to Item 6. 46. 37. The kit according to claim 36, wherein the first and second immunoreactive substances specifically bind to each other. 47. 47. The kit of claim 46, wherein one of said immunoreactive substances is an antibody and the other is an antigen specifically bound by said antibody. 48. 47. The kit according to claim 46, wherein the first immunoreactive substance is an antibody, and the second immunoreactive substance is an antigen specifically bound by the antibody. 49. 30. The kit of claim 29, comprising a core member disposed in intimate contact with the element at one end thereof. 50. 37. The kit of claim 36, including a core member disposed in intimate contact with the element at one end thereof.