Abstract: An analyte, such as an antigen, is initially contacted with a receptor (antibody) bound to a solid support, in the absence of tracer, followed by removal of unbound analyte and contacting with tracer. By separately contacting the receptor with analyte and tracer, sensitivity is increased.

Abstract: Automated assay for qualitative determination of thyroid hormone binding capacity of a serum sample in which serum and T.sub.3 tracer are caused to flow through a chamber containing a T.sub.3 binder supported on a solid support. The amount of T.sub.3 tracer which passes through the chamber, and the amount of T.sub.3 tracer bound to the binder in the chamber are determined to thereby determine the percent of bound T.sub.3 tracer. Such percent is then compared with the percent of T.sub.3 tracer bound in a referenced sample to qualitatively determine the T.sub.3 binding capacity of the serum sample.

Abstract: An immobilized immunoadsorbent for use in immunoassay and radioimmunoassay procedures includes, in a preferred form, a mass of superficially porous refractory particles having a water insoluble polymer, such as dextran, bonded thereto. The polymer in turn has bonded to it, by covalent bonds, antibodies capable of binding a specific antigen thereto and stoichiometrically releasing the bound antigen by the use of a rinsing solution which does not adversely affect the binding of the antibody to the polymer. Preferably, each of the porous particles includes an impervious core which has joined thereto sufficient layers of microparticles to form an outer porous coating on the core. Methods of forming such an immunoadsorbent and for using the same and structure for supporting the same.

Abstract: An immobilized immunoadsorbent for use in immunoassay and radioimmunoassay procedures includes, in a preferred form, a mass of superficially porous refractory particles having a water insoluble polymer, such as dextran, bonded thereto. The polymer in turn has bonded to it, by covalent bonds, antibodies capable of binding a specific antigen thereto and stoichiometrically releasing the bound antigen by the use of a rinsing solution which does not adversely affect the binding of the antibody to the polymer. Preferably, each of the porous particles includes an impervious core which has joined thereto sufficient layers of microparticles to form an outer porous coating on the core. Methods of forming such an immunoadsorbent and for using the same and structure for supporting the same are also disclosed.

Abstract: An immobilized immunoadsorbent for use in immunoassay and radioimmunoassay procedures includes, in a preferred form, a mass of superficially porous refractory particles having a water insoluble polymer, such as dextran, bonded thereto. The polymer in turn has bonded to it, by covalent bonds, antibodies capable of binding a specific antigen thereto and stoichiometrically releasing the bound antigen by the use of a rinsing solution which does not adversely affect the binding of the antibody to the polymer. Preferably, each of the porous particles includes an impervious core which has joined thereto sufficient layers of microparticles to form an outer porous coating on the core. Methods of forming such an immunoadsorbent and for using the same and structure for supporting the same are also disclosed.

Abstract: Apparatus for radioimmunoassay provides a continuously reusable short cycle analytical system of particular use in biochemical analysis such as the determination of steroids, hormones, polypeptides, viruses, vitamins, drugs, and the like. The apparatus disclosed samples a mixture of an unlabelled antigen sample and a known concentration of labelled antigen, bringing the mixture into contact with a mass of appropriate antibody that has been immobilized thereby to bind at least part of the mixed antigen to the antibody. The amount of bound and/or unbound labelled antigen is detected and counted and, by use of previously prepared standards, the unknown concentration of unlabelled antigen is found. The still immobilized antibody is regenerated for immediate reuse by rinsing it with a selected eluting solution that is capable of breaking the antigen-antibody. Alternate ways of immobilizing the antibody are described. Several suitable eluting solutions are disclosed.