Abstract: The present invention provides a device, test cards, methods and kits which are useful for determining the particle fraction and rate of viscosity of a fluid sample, the presence of an analyte in a fluid sample, or the aggregation of particles in a fluid sample to detect an analyte or as an immunologic assay.

Abstract: A multizone test device for the determination of analyte from a liquid test medium upon contact with the liquid test medium and a labeled reagent comprising a chemical group having a detectable physical property. The test device preferably comprises multilayers including a reagent layer incorporated with an immobilized reagent and a detection layer incorporated with an immobilized form of a binding substance for the labeled reagent. The immobilized reagent and the labeled reagent comprise specific binding partners which will bind to each other dependent upon the amount of analyte present. Labeled reagent which does not become bound to the immobilized reagent in the reagent layer migrates into the detection layer and becomes bound to and immobilized by the immobilized binding substance therein.

Abstract: A multizone test device for the determination of analyte from a liquid test medium upon contact with the liquid test medium and a labeled reagent comprising a chemical group having a detectable chemical property. The test device preferably comprises multilayers including a reagent layer incorporated with an immobilized reagent and a detection layer incorporated with an immobilized form of an interactive detection reagent for the labeled reagent. The immobilized reagent in the reagent layer and the labeled reagent comprise specific binding partners which will bind to each other dependent upon the amount of analyte present. Labeled reagent which does not become bound to the immobilized reagent in the reagent layer migrates into the detection layer and interacts with the immobilized interactive detection reagent therein which results in the localized generation of a detectable reaction product which preferably is also immobilized in the detection zone.

Abstract: A heterogeneous specific binding assay method for determining the amount of a suspected analyte in an aqueous test medium wherein a reaction mixture is formed by combining the test medium with assay reagents including a labeled reagent, an immobilizable component, and a binding substance which causes the immobilizable component to precipitate. Free and bound species of the labeled reagent are formed as a function of the amount of the analyte in the test medium. One of the free and bound species of the labeled reagent is immobilized by binding of the immobilizable component with the binding substance. The immobilized labeled reagent is seperated from labeled reagent which has not been immobilized, and the amount of label in the labeled reagent in one of the separated fractions is determined and related to the amount of analyte in the test medium.

Abstract: A homogeneous specific binding assay device, a method for its preparation, and a method for its use in determining a ligand, such as antigen, hapten, or antibody, in, or the ligand binding capacity of, a liquid sample. The test device comprises a solid carrier member, such as a fibrous web matrix, e.g., paper, or a polymeric film or gel, incorporated with reagents for a homogeneous specific binding assay system which produces a detectable response, usually an electromagnetic radiation signal, that is a function of the presence or amount of the ligand in or the ligand binding capacity of the sample. Useful homogeneous specific binding assay systems include those involving enzyme substrate labels, enzyme prosthetic group labels, and enzyme labels. The detectable response preferably is a luminescent, fluorescent, spectrophotometric, or colorimetric response, which is measurable by visual observation or instrument means.

Abstract: A device for the quantitative determination of heparin in mammalian blood plasma, a method for the preparation of such device and a method for determining the plasma's heparin concentration using the device. The device, which is prepared using a freeze-drying technique, comprises a first upper layer of a carrier matrix material containing a buffer, AT-III and thrombin and a second, lower layer of a carrier matrix containing a thrombin sensitive fluorogenic or chromogenic substrate being capable of interacting with thrombin in such a manner that a time-related chemical change detectable by fluorometric or spectrophotometric means takes place when thrombin and the substrate are contacted in a suitable liquid environment.

Abstract: Disclosed is a method and device for the quantitative determination of AT-III in mammalian blood plasma. The method involves contacting a plasma sample containing excess heparin with a 3 layered reagent strip comprising:i. a first upper layer of a bibulous material containing thrombin and a buffer;ii. a second lower layer of a bibulous material containing a fluorogenic or chromogenic substrate capable of interacting with thrombin in a time related chemical manner; andiii. a bottom layer of water impermeable material.The chemical change in the strip is determined as a function of time and this change is compared with that obtained in samples containing known amounts of AT-III.

Abstract: A homogeneous specific binding assay element, a method for its preparation, and a method for its use in determining a ligand in or the ligand binding capacity of a liquid sample are disclosed. The test element comprises a solid carrier incorporated with reagents for a homogeneous specific binding assay system which produces a detectable response, usually an electromagnetic radiation signal, that is a function of the presence or amount of the ligand in or the ligand binding capacity of the sample.

Abstract: A homogeneous specific binding assay element, a method for its preparation, and a method for its use in determining a ligand in or the ligand binding capacity of a liquid sample. The test element comprises a solid carrier incorporated with reagents for a homogeneous specific binding assay system which produces a detectable response, usually an electromagnetic radiation signal, that is a function of the presence or amount of the ligand in or the ligand binding capacity of the sample.

Abstract: A homogeneous specific binding assay device, a method for its preparation, and a method for its use in determining a ligand, such as antigen, hapten, or antibody, in a liquid sample. The test device comprises a solid carrier member, such as a fibrous web matrix, e.g., paper, or a polymeric film or gel, incorporated with reagents for a homogeneous specific binding assay system which produces a detectable response, usually an electromagnetic radiation signal, that is a function of the presence or amount of the ligand in the sample.

Abstract: A multilayer analytical element for detecting a ligand in or the ligand binding capacity of a liquid sample of the type having a reagent layer(s) incorporating reagents which are responsive to the ligand in or the ligand binding capacity of the sample to give a detectable response, a radiation reflecting layer, and a support layer, the improvement wherein the reagent layer(s) is a radiation diffusing layer and the radiation reflecting layer is a radiation nondiffusing reflecting layer which is (a) interposed between the reagent layer(s) and the support layer; (b) impermeable to the ligand, reagents of the reagent layer(s), and products of their interreaction; and (c) inert to the ligand, reagents of the reagent layer(s), and products of their interreaction.