Abstract: An article for performing solid-phase immunological assays and methods for performing assays utilizing such article. A solid-phase support suitable for immunological assays is stained with an organic dye that has a net-positive charge and a hydrophobic aromatic ring structure. An immunologically reactive component having a net-negative charge, such as a whole cell, is securely immobolized by the dye to the support through noncovalent interactions. A sample of biological fluid may be added to the article to which the immunologically reactive component has been immobilized to effect binding of antigens or antibodies in the sample which are specific to the immobilized component. The presence of the antigen-antibody complex may then be determined by any known means.

Abstract: An article for performing solid-phase immunological assays and method for performing assays utilizing the article of the invention. A solid-phase support suitable for immunological assays is stained with an organic dye that has a net-positive charge and a hydrophobic aromatic ring structure. An immunologically reactive component having a net-negative charge is immobilized by the dye to the support through non-covalent interactions. The immunologically reactive component is tightly bound by the organic dye. This is advantageous when performing immunological assays utilizing automated washing instruments. A sample of a biological fluid is added to the article having the immunologically reactive component bound thereto to detect the presence of antigens or antibodies in the biological fluid specific for the bound immunological component. The presence of the antigen-antibody complex may be determined by any known method.