Abstract: Methods are provided for rapidly determining a number of parameters in a few determinations. Particularly, the method is applicable to blood typing, determining the blood type as to the ABO and Rh type, as well as the determination of isoantibodies to the antigens. The method employs fluorescent particles having a plurality of fluorescers, where the presence or absence of light emission of a particular wavelength can be determined.

Abstract: Improved sensitive immunoassays are provided involving channeling involving one, usually two enzymes, where the enzymes are related by the product of one enzyme being the substrate of the other enzyme. A dispersed aggregation is formed in the assay medium of (1) the analyte, (2) one of the enzymes bound to a second binding member ("SBM") (enzyme - SBM conjugate) which conjugate is non-covalently bound to a first binding member ("FBM"), and (3) a multiplied amount of the other enzyme bound in the complex. The large amount of enzyme or reactant in the complex is achieved by having a multiplicity of linkages binding the enzyme or reactant directly or indirectly to FBMs. The enzyme channeling provides for a detectable signal which can be related to the amount of analyte in the medium.

Abstract: Assays are provided employing particles and absorbent particles, wherein the absorbent particles substantially inhibit fluorescence when bound to the fluorescent particles through specific non-covalent binding.

Abstract: Enzyme channeling assay is provided employing a solid non-porous surface to which is bound a member of a specific binding pair and an enzyme. A complementary member of a specific binding pair is conjugated to second enzyme, so that the amount of second enzyme which becomes bound to said solid non-porous surface by the binding of a specific binding pair(s) is related to the amount of analyte in the liquid assay medium with which the solid surface is in contact. The first and second enzymes are related by the product of one being the substrate of the other. The turnover of the substrate formed by one of the enzymes results in a detectable product, which can be related to the amount of analyte in the medium.

Abstract: A device is disclosed for collecting a liquid sample and diluting the liquid sample by virtue of being adapted for use with a container having a volume of diluting liquid. The device comprises a housing adapted for mating with the container where the mated housing and container form a chamber. A bibulous pad is attached to the housing for collecting a predetermined amount of a liquid sample. Additionally, the device, when used with the container, creates a pressure differential between the interior of the housing and the chamber. The pressure differential is sufficient to move a predetermined volume of the diluting liquid through the bibulous pad and into the housing. The device can be used for assaying for a component of a sample. The device has particular use in immunochromatography and for convenience can also contain a strip of bibulous material confined in the housing.

Abstract: A sampling device is disclosed. The device comprises a capillary tube having a first orifice for collecting and dispensing a liquid at one end of the tube and a second orifice at the other end of the tube. A chamber encloses the second orifice. The device has a small opening to the outside atmosphere, other than the first orifice, communicating with the capillary tube. Also included is substantially non-compressible means movable with respect to said opening for concomitantly sealing said opening and forcing air from said chamber through said capillary tube.

Abstract: Fluorescent antigen conjugates are provided comprising antigens covalantly bonded to at least one 2,7-dialiphatic substituted-9-phenyl-6-hydroxy-3H-xanthen-3-one, wherein the 1- and 8-positions are unsubstituted. Also provided are novel fluorescent compounds absorbing at wavelengths in excess of 500 nm, having active functionalities for linking to the antigen. Finally, methods are provided for analyzing antigens in serum, whereby serum interference is avoided.

Abstract: Methods are provided for rapidly determining a number of parameters in a few determinations. Particularly, the method is applicable to blood typing, determining the blood type as to the ABO and Rh type, as well as the determination of isoantibodies to the antigens. The method employs fluorescent particles having a plurality of fluorescers, where the presence or absence of light emission of a particular wavelength can be determined.

Abstract: A sensitive method for identifying red blood cell antigens or antibodies thereto is provided. A fluorescent bead is conjugated to a receptor specific for a red blood cell antigen (ligand) or alternatively with an antigen for determination of antibodies. The conjugate is mixed with a red blood cell containing composition. A change in fluorescence compared with a control reveals the presence or absence of the antigen or antibody.

Abstract: An assay method and compositions are provided for determining the presence of an analyte in a sample. The analyte is a member of an immunological pair (mip) comprising ligand and receptor. By providing a first measurement surface capable of specifically binding a labelled reagent in an amount depending upon the presence of analyte in the sample and a second calibration surface capable of binding a second labeled reagent in a manner unaffected by the presence of analyte in the sample, calibration of individual tests can be accomplished simultaneously with the performance of the test itself. A signal producing system includes an enzyme, a catalyst usually bonded to a mip which defines the first labeled reagent for binding to the measurement surface and the same catalyst conjugated to a ligand capable of binding to the calibration surface. Preferably, both labeled reagents have the same composition and the calibration surface includes anti-(first catalyst).

Abstract: An assay method and compositions are provided for determining the presence of an analyte in a sample. The analyte is a member of an immunological pair (mip) comprising ligand and receptor. By providing a first measurement surface capable of specifically binding a labelled reagent in an amount depending upon the presence of analyte in the sample and a second calibration surface capable of binding a second labeled reagent in a manner unaffected by the presence of analyte in the sample, calibration of individual tests can be accomplished simultaneously with the performance of the test itself. A signal producing system includes an enzyme bonded to a mip which defines the first labeled reagent for binding to the measurement surface and the same enzyme conjugated to a ligand capable of binding to the calibration surface. Preferably, both labeled reagents have the same composition and the calibration surface includes anti-(first enzyme).

Abstract: Improved results are achieved in fluorochromasia lymphocytotoxicity for cell typing by adding antifluorescer to reduce background fluorescence as a result of cell lysing.

Abstract: A method for determining a member of a specific binding pair-ligand and receptor (antiligand). Reagents employed include a first modified member which provides an electrical field due to the presence of a plurality of ionic charges and a second modified member labeled with a component of a signal producing system, which system may have one or more components. The average proximity in the assay medium of the first and second modified members is related to the amount of analyte, where the observed signal from the signal producing system is related to the effect of the electrical field on the signal producing system.Also, compositions are provided, as well as reagents, in predetermined ratios for optimizing the signal response to variations in analyte concentration.

Abstract: Fluorescent antigen conjugates are provided comprising antigens covalantly bonded to at least one 2,7-dialiphatic substituted-9-phenyl-6-hydroxy-3H-xanthen-3-one, wherein the 1- and 8-positions are unsubstituted. Also provided are novel fluorescent compounds absorbing at wavelengths in excess of 500 nm, having active functionalities for linking to the antigen. Finally, methods are provided for analyzing antigens in serum, whereby serum interference is avoided.

Abstract: .beta.-D-Galactosidase conjugates for use in homogeneous immunoassays. .beta.-D-Galactosidase is conjugated with analytes and the resulting conjugates are combined with receptors for the analyte and a sample suspected of containing the analyte. The resulting enzymatic activity is compared to standard assay media for quantitative determination of the analyte.

Abstract: Methods and compositions for assaying for coenzymes having N-substituted 1,4-dihydropyridyl as the active portion of the prosthetic group. The conversion of NAD to NADH is widely measured both for determining NAD-NADH (including the analogs thereof) dependent enzymes and enzymes that can be coupled to NAD-NADH dependent enzymes, and for determining ligands or receptors in competitive protein binding assays. Antibodies specific for NADH in the presence of NAD are employed, providing enhanced fluorescence over the normal fluorescence of unbound NADH. By determining the rate of formation of NADH or the concentration of NADH, the analyte or enzyme of interest can be determined.

Abstract: An assay method and compositions are provided for determining the presence of an analyte in a sample. The analyte is a member of an immunological pair (mip) of immunogens--ligand and receptor. The method has two basic elements: a solid surface to which one of the members of the immunological pair is bonded and a signal producing system, which includes a catalytic member bonded to a mip, which signal producing system results in a measurable signal on said solid surface related to the amount of analyte in the medium. The signal generating compound is produced without separation of the catalyst labeled mip bound to the solid surface from the catalyst labeled mip free in solution.

Abstract: Novel biological assay method for determining the presence of a specific organic material by employing a modified enzyme for amplification. By employing receptors specific for one or a group of materials (hereinafter referred to as "ligands") and binding an enzyme to the ligand or ligand counterfeit to provide an "enzyme-bound-ligand", an extremely sensitive method is provided for assaying for ligands. The receptor when bound to the enzyme-bound-ligand substantially inhibits enzymatic activity, providing for different catalytic efficiencies of enzyme-bound-ligand and enzyme-bound-ligand combined with receptor.The receptor, ligand and enzyme-bound-ligand are combined in an arbitrary order and the effect of the presence of ligand on enzymatic activity determined. Various protocols may be used for assaying for enzymatic activity and relating the result to the amount of ligand present.

Abstract: Method and compositions are provided for performing protein binding assays involving a homologous pair consisting of ligand and receptor for the ligand. The method employs a label conjugated to a member of said homologous pair and a uniformly dispersed discontinuous phase of discrete particles in a continuous aqueous phase, where the discrete particles create microenvironments which allow for discrimination between the label associated with the particle--in a discontinuous phase--and the label in the continuous phase.Various conjugates and particles are provided which find use in the subject method.

Abstract: Fluorescent antigen conjugates are provided comprising antigens covalently bonded to at least one 2,7-dialiphatic substituted-9-phenyl-6-hydroxy-3H-xanthen-3-one, wherein the 1- and 8-positions are unsubstituted. Also provided are novel fluorescent compounds absorbing at wavelengths in excess of 500 nm, having active functionalities for linking to the antigen. Finally, methods are provided for analyzing antigens in serum, whereby serum interference is avoided.