Abstract: A specific binding member such as an antigen or antibody is immobilized by covalent attachment to a solid phase such as a latex microparticle. The solid phase is reacted with a heterobifunctional or homobifunctional coupling agent to form a complex that is then reacted with a dithiol compound to form a thiolated solid phase. A specific binding member is reacted with the coupling agent to form a complex which is then reacted with the thiolated solid phase to link the specific binding member to the solid phase through thioethers. Alternatively, the dithiol compound may be reacted with the specific binding member/coupling agent complex to form a thiolated complex that is reacted with the solid phase/coupling agent complex. The coupling agent may contain a spacer. In another embodiment, the solid phase is reacted with a disulfide compound to form a complex and the complex is reacted with a reductant to form a thiolated solid phase which is reacted with a specific binding member/coupling agent complex.

Abstract: A novel material and device useful in solid-phase binding assays to determine the presence or amount of an analyte in a test sample, particularly antigens or antibodies, is disclosed. The material comprises a porous matrix of fibers and a plurality of substantially spherical, solid particles having an average diameter of from about 0.1 to about 5 microns. The particles are retained and immobilized upon the fibers of the matrix. Preferably, the particles have on their surfaces a substance capable of reaction with the analyte in the sample, and the average diameter of the particles is less than the average pore size of the matrix. The device, in a preferred embodiment, comprises a substantially planar layer of the described material.

Abstract: An immunoassay which is capable of simultaneously detecting any desired number of antigens of one infectious agent, or combinations of antigens of several infectious agents, or any desired number of immunoglobulins of one infectious agent, or combinations of immunoglobulins of several infectious agents on a single solid support. A test sample is contacted with a solid support on which one or more antigens are immobilized as discrete test sites. Antigen-antibody complexes are formed and detected on the solid support.