abstract |
An immunoassay process for the detection of an antigen in a sample, which comprises: (a) forming a mixture of the sample with (1) a preformed complex of a primary antibody and a secondary binding macromolecule therefor, wherein the primary antibody is present at low concentrations and has substantial specificity for the antigen, the secondary binding macromolecule has substantial affinity for the Fc portion of the primary antibody, and the second binding macromolecule is affinity purified; and with (2) a detectably labeled form of the antigen; (b) incubating the mixture formed in step (a) for a time sufficient to allow the antigen and the detectably labeled antigen to competitively bind to the primary antibody of the preformed complex; (c) detecting the separated complex or the separated suspension medium. |