Abstract: A radial immunodiffusion enzyme assay method for the simple testing of pseudorabies antibodies in swine and other animals. Agar test plates are provided including an underlying adherent coating of solubilized non-infectious swine pseudorabies antigen. Blood or blood serum samples from affected animals are placed in wells punched in the agar layer and allowed to incubate overnight. The agar gel is then removed. The resulting antigen layer with bound antibodies from the samples is washed and reacted with enzyme conjugated anti-swine immunoglobulin. The reaction is visualized by overlaying the bound conjugate layer with agar containing a color producing enzyme substrate. The diameters of resulting colored zones are correlated with the titers obtained by the official virus neutralization test. Methods of preparing antigen and antigen coated test plates are disclosed along with testing kits for carrying out the test procedure in the field.

Abstract: A method for the determination of antigens or antibodies in a fluid by incubation of particles, which have antigens on the surface, and antibodies, whereby either the antigens or the antibodies are of known specificity is described. This method comprises introducing the antigen/antibody complex into a container having a conical-shaped or keel-shaped bottom recess, whereby at least the recess of the container is coated with an immunoglobulin-building component which is directed against the antibodies. After centrifugation the amount of the sediment is determined, which indicates whether the antigen or antibody to be determined is present or not.

Abstract: Method and apparatus for use in accurately measuring the binding reactions occurring between a predetermined class of components in a liquid specimen and their corresponding binding conjugates coated on separate test regions of a carrier. The carrier further includes a reference region that is uncoated, and the carrier is adapted for simultaneous contact of all of its regions with the liquid specimen. Any resulting binding reaction on each test region indicates both specific binding to the coated component as well as non-specific binding, and any resulting binding reaction on the reference region indicates merely non-specific binding. The measurements for the test regions are all reduced by an amount determined in accordance with the measurement for the reference region, to reduce the effects of non-specific binding on those measurements and thereby provide accurate measurements of the specific binding on each coated component.

Abstract: An assay apparatus and methods employing total internal fluorescence to define a thin observed volume of a multi-phase suspension from which the suspended phase, because of its size and shape, is substantially excluded. Observations of the fluorescence of a known quantity of fluorescent material introduced into a known volume of the sample containing the observed volume permits quantitation of the volumes of the suspended and suspending phases.

Abstract: The disclosed methods improve conventional agglutination processes for assaying immunoreactive and like substances, primarily by improving the measurement of the agglutination itself. Suspensions containing agglutinated particles are automatically inspected, preferably intermittently during the agglutinating reaction, and the resulting data are processed to identify individual particle aggregates of a selected limited class, which may, for example, comprise aggregates having sizes within a limited size interval. The numbers of such aggregates are compared with corresponding reference values obtained with standard solutions and suitable controls to evaluate the concentration of one of the reactive substances, or other information. The aggregate size intervals and other parameters which are used to define aggregate classes are preferably selected with attention to the detailed behavior of each test system.

Abstract: Histamine is detected or determined selectively in a sample by causing the sample to contact glass microfibers in such a quantitative proportion as will permit the histamine present to bind to the fibers. The amount of bound histamine may be determined by competitive determination in the presence of labelled histamine on the basis of a standard curve, or may be determined directly by conventional coupling reactions.The method is simple and particularly useful for allergy diagnostics because it exhibits good correlation with known fluorometric methods.

Abstract: Apparatus and method for an immunoassay of a binding reaction between a ligand and an antiligand which are typically an antigen and an antibody, including a spatial pattern formed by a spatial array of separate regions of antiligand material, and ligand material dispersed to interact with the spatial array of separate regions of antiligand material for producing a binding reaction between the ligand and the antiligand in the spatial patterns and with the bound complexes labeled with a particular physical characteristic. A source of input energy and with the input energy at a particular spectrum for interacting with particular physical characteristic of the labeled binding reaction.

Abstract: Apparatus and method for testing the sufficiency of sterilization includes a test tube having a distal end in which a bacterial spore element is disposed. A sealed glass ampule containing a sterile liquid culture medium is disposed in the test tube and a plunger having a fenestration closed with a hydrophobic filter is fitted slidingly in the open end of the test tube. In use, the apparatus is exposed to sterilization, and thereafter the plunger is pushed down into the test tube to engage the ampule to slide the latter into engagement with an ampule-engaging means to thereby fracture or break the ampule so that the contents of the ampule are released into the test tube to contact the spore element, whereby the apparatus is then subjected to incubation, the sufficiency of the sterilization being thereby determined.

Abstract: Method of separating A.sub.14 -.sup.125 I-insulin from heterogeneously labeled insulin molecules for biological studies which involves iodating insulin in a controlled manner, selectively absorbing the insulin from the iodination procedure in a tightly packed bed of octadecylsilane bonded to silica employing reverse phase liquid chromatography principles, thereafter eluting large and small radioactive and nonradioactive materials such as damaged insulin, various contaminants and polar materials from the bed with dilute trifluoroacetic acid, thereafter eluting the intact .sup.125 I-insulin from the bed with a mixture of acetonitrile and dilute trifluoroacetic acid and then separating the A.sub.14 -insulin by high performance liquid chromatography or ion exchange chromatography.

Abstract: A highly sensitive and rapid method for quantitatively assaying analytes in liquid media by directly measuring changes in particle size distribution of reagent particles having analyte insolubilized thereon in a system undergoing antibody-induced aggregation has been developed. The amount of analyte initially present can be determined by measuring the change in the distribution of particle size with time, the concentration of a particular size particle at a given time, the rate of formation of a particular size particle, or the steady-state maximum concentration for a particular size particle.

Abstract: Crude interleukin-2 extract is subjected to group-selective dye-ligand absorption chromatography in one or more stages of purification with a matrix-gel medium consisting of a Blue A ligand or variant thereof or of a Green A ligand in a concentration of approximately 1.5 to 3.0 mg/ml of expanded matrix at a pH of approximately 6.8 to 8.5, a temperature of approximately 4.degree. to 40.degree. C., and a flowthrough rate of approximately 10 to 100 ml/h, employing an eluent. Either PHA-free or extremely pure interleukin-2 is obtained, depending on the overall number of purification stages.

Abstract: A process for the detection of an antigen or antibody in a specimen which process comprises:(a) contacting said specimen with a substrate having bound thereon a mixture of antigens and antibodies to said antigen or antibody in said specimen, said antibodies and said antigens bound to said substrate being separately bound to said substrate and not in the form of an immune complex, incubating the so-contacted substrate and washing the substrate;(b) contacting the washed material of step `a` with a radioactive material labeled or enzyme labeled antibody or antigen, incubating the so-contacted material and washing the same; and(c) effecting radioimmunoassay if said antibody or antigen is radioactive or enzyme labeled immunoassay is said antibody or antigen is enzyme labeled.

Abstract: Methods for determining the presence of antigens or antibodies in an aqueous sample or presence of antigens on the surface of cells. A preferred embodiment employs fluorescent antigens which compete with the sample antigens for antibody binding sites. The antibodies are deposited on a support surface means in alternating patterns. The surface means and fluorescence detector are translocated with respect to each other and a signal generated by the detection of the repeating pattern of fluorescence. The signal is analyzed by means of a gated integrator responsive to a gate track control means also located on the surface means. Immunoassay methods having increased sensitivity are thereby obtained.

Abstract: A particle washing system and method of use provides for the placement of the fluid containing the desired particles within an inner tube having near the bottom thereof an orifice plugged with a material for sealing the particulate containing fluid from a wash fluid under forces substantially equal to 1G. The inner tube is positioned within an outer tube which contains a wash fluid having a density at least equal to that of the particle containing solution but less than that of the particles. Application of centrifugal force, substantially greater than 1G, and directed toward the bottom of the outer tube, causes the sealing material to be dislodged thereby permitting the particles to move through the orifice and through the outer solution. Thus the particles are collected from the inner solution, washed by the outer solution, and pelleted at the bottom of the outer tube.

Abstract: Method and apparatus are provided for carrying out multiple simultaneous transfers of fluid. The method and apparatus are particularly directed toward immunoassays wherein immunologically active compounds, such as antigens and haptens, are detected through their associated antibodies. The device relies on the ability to transfer fluids, such as biological samples and reagents, between a reservoir and an associated receptacle. By providing a receptacle having a port at its lower end and which is otherwise hermetically sealed, such fluid transfer can be effected by immersing the port beneath the surface of the fluid in the reservoir and manipulating the pressure on the remaining surface area outside the port. The transfer of biological fluids at positive pressure provides enhanced fluids flow characteristics, particularly reduction or elimination of the tendency of these fluids to froth or bubble.

Abstract: A method of determining the concentration of an antigen in a sample solution comprising(a) coating an antigen-protein conjugate onto a solid matrix,(b) conjugating an enzyme to an antibody specific for said antigen,(c) to a known quantity of a solution containing the antibody-enzyme conjugate of (b) adding a specified quantity of a sample containing an unknown amount of the antigen whose content is to be determined,(d) contacting the coated solid matrix of (a) with the solution (c) and incubate so as to effect binding between the antibody and antigen, some of the antigen being that from the sample and some being that on the solid matrix,(e) removing the solid matrix from the solution and washing,(f) immersing the solid matrix in a solution containing a known amount of an enzyme-substrate which is acted upon by the enzyme so as to effect reaction between the enzyme and enzyme-substrate to produce a product, and then separating the solid matrix from the solution of enzyme-substrate, and(g) then measuring the so

Abstract: An apparatus and method for transferring fluids (48) in a multi-liquid reagent protocol. Serum/plasma for a therapeutic drug assay is first obtained and mixed with a fluorogenic drug reagent (48) within a first cuvette (38). After mixing, the reaction product is accessed through a small opening (50) by tipping the cuvette (38). Fluid transfer is effected through a capillary tube (12) having an accurately calibrated bore (14), the capillary tube (12) being held between its open distal and proximal ends (30, 32) by a gripping sleeve (24). The capillary tube holder (10) is then inserted into a second cuvette where it suspends the capillary tube (12) over the liquid level (54) of a second reagent (56) in second cuvette (40). By vigorous up-and-down shaking of the second cuvette (40), the contents of the capillary tube (12) are discharged substantially uniformly throughout the liquid second reagent (56) in a short time period.

Abstract: Fluorescent immunoassay apparatus and method employing a disposable consisting, in a preferred embodiment, of a short length of precise diameter capillary tubing having an axially disposed optical fiber to which is immobilized a monolayer of a component of the antibody-antigen complex (e.g., an antibody), an inert diluent, and a preload of a known amount of tagged complement to the immobilized component (e.g., a fluorescent-tagged antigen). The dimensions of the fiber and the capillary tubing are chosen so as to allow the tube to fill itself by capillary action once an end of the tube is immersed into the sample. Precise timing and ballistic measurements may, if desired, be avoided by insuring the incubation time is larger than the diffusion time necessary to scavenge the volume between the fiber and the capillary tubing. Fluorimetric measurement is made by total reflection fluorescence techniques.

Abstract: The use of colloidal gold as a bright field light microscopic marker for the immunocytochemical localization of antigens in histological sections, namely the two step or the bridge immuno gold staining method.

Abstract: A technique for measuring the degree of an antigen-antibody reaction by preparing a suspension of insoluble microscopic carrier particles of at least one type carrying an antigen, an antibody or a hapten, forming an agglutination promoting or inhibiting reaction system among the insoluble carrier particles based on an antigen-antibody reaction using the suspension and one or more antigen, antibody or hapten, irradiating the solution of the reaction system with laser light and detecting the light scattered from the reaction system at one or more specific angles, detecting a signal indicative of one or more specific frequency bands from the resulting scatter spectrum, and thenceforth calculating the quantity of antigen, antibody or hapten in a specimen on the basis of the detected signal. The intensity spectrum output of filter 11 for frequency band selection is in the form of a square root and is converted into the original intensity spectrum by means of a squaring circuit 12.

Abstract: A method of measuring the degree of partitioning of a labeled species between free and bound states which involves the use of an insoluble porous monolith having a means for binding a portion of the labeled species within the pores thereof, which monolith is capable of substantially attenuating the signal emitted by labeled species subsequently bound within the pores thereof.

Abstract: A particle agglutination reaction is detected with the aid of a reaction vessel of flow cell type having an inlet, an outlet and an inclined passage communicating the inlet and outlet to each other. A test liquid containing particles is supplied into the passage via the inlet and is retained stationary therein for a given time period. Particles descending upon an inclined bottom surface of the passage form at first a stable base layer due to regular steps formed in the bottom surface. When a particle agglutination reaction has occurred, a uniformly deposited particle pattern is formed on the inclined bottom surface, while in case of non-agglutination reaction, the particles descending upon the inclined bottom surface roll down along the base layer and are collected at the lowermost portion of the passage. By detecting the particle pattern formed on the inclined bottom surface, it is possible to detect the agglutination reaction accurately.

Abstract: A reaction vessel, test device, and method of detection or measurement are disclosed, featuring the use of at least two operatively connected zones formed by transport surfaces spaced apart throughout most of the zones a capillary distance. The zones are fluidly connected by meniscus control means effective to stop capillary flow of the liquid from one zone to the other, until an externally generated actuation pressure is applied.

Abstract: In the course of a reaction in which one of the reactants is on the surface of carrier particles in a solution and another of the reactants is tagged with a fluorescent substance, some of the fluorescently tagged reactant attaches to, or is displaced from the carrier particle. The present invention relates to a method and device for determining the amount of fluorescently-tagged reactant which is attached to the carrier particle or which is free in solution, without physically separating the carrier particles from the solution. In a particular application of the invention (immunoassay) the reaction is between antibodies and antigens, and from the amount of fluorescently-tagged reactant which is attached to the carrier particle one can determine the unknown amount of antigen in a sample.

Abstract: Fluroroimmunoassay of fluoroescently tagged species using pulsed high intensity light, and single or paired fluorescent detectors, and polarizing the activating radiation and both fluorescent radiation outputs and apparatus for carrying out such assay is disclosed.

Abstract: In the course of a reaction in which one of the reactants is on the surface of carrier particles in a solution and another of the reactants is tagged with a fluorescent substance, some of the fluorescently tagged reactant attaches to, or is displaced from the carrier particle. The present invention relates to a method and device for determining the amount of fluorescently-tagged reactant which is attached to the carrier particle or which is free in solution, without physically separating the carrier particles from the solution. In a particular application of the invention (immunoassay) the reaction is between antibodies and antigens, and from the amount of fluorescently-tagged reactant which is attached to the carrier particle one can determine the unknown amount of antigen in a sample.

Abstract: In a method of assay for a trace component such as antigen, antibody or enzyme utilizing immunochemical reaction or enzyme reaction in combination with photographic detection system comprising measuring optical density of a silver image formed in proportion to the antigen, antibody or enzyme to be measured, a novel analysis sheet comprising a support having provided thereon, in succession, a water absorbing layer and a silver halide emulsion layer is employed. The analysis sheet essentially increases the amount of water absorbed so that the analysis sheet is extremely effective for improving detection sensitivity.

Abstract: In an immunochemical measurement method of an antigen or antibody which comprises competitively reacting an antigen or antibody labelled with spectral sensitizer and an antigen or antibody to be measured, bringing either the reaction product of immune reaction or the unreacted component into contact with silver halide, exposing the same to light having a wavelength which the spectral sensitizer absorbs, developing the exposed silver, and, measuring optical density of the thus formed silver image and/or colored dye, the contact with silver halide is performed in the presence of a specific hydrazine compound. Thus, detection sensitivity is markedly improved.

Abstract: A method and apparatus for washing the solid annular pieces used in immune methods, i.e. the so-called EIA-rings, and for coating such rings with a reagent, as well as for the dispensing of the rings. The EIA-rings are fitted, one after the other, into a tubular container part, which is open at both ends. To the bottom end of the container part an intake tip is attached, and to the other end a device for drawing and exhausting a liquid through the intake tip into the container part. The container part enclosing the EIA-rings is then sealed at both ends until the upper end of the container part is opened for dispensing the rings. The opened end is connected to a dosage device, the intake tip of the container part is removed and the EIA-rings are dispensed by means of the device.

Abstract: This invention relates to a method and to apparatus for chemical and biochemical analyses which employ an energy-transmissive core and may employ one or more sheaths which selectively absorb, react with, and/or filter an analyte or a product of an analyte. The core is transmissive to a chosen energy carrier and it has an inlet end and an outlet end. Between these ends it has an extended length. The passage of energy through the core is modified by reason of events which occur in one or more of the sheaths or in the case where no sheath is employed, by reason of events which occur in an ambient fluid. The resulting modification of the transmitted energy is a measure of such events which in turn are a measure of the analyte. The energy may be any of several types of energy which can be transmitted through the core from end to end and which is susceptible to modification by reactions in the sheath or sheaths or ambient fluid. The energy may be electromagnetic, electrical or sonic.