Immunoassay for quantitatively determining antigens.

摘要

An immunoassay for quantitatively determining an antigen in a sample is disclosed, which comprises immobilizing a primary antibody in a purified state or in a diluted serum to the surface of a carrier via an affinity ligand, particularly protein A, immobilizing an antigen to be determined to the primary antibody, and reacting a labelled secondary antibody with the antigen. This method can attain a markedly improved identification limit and measurement limit which have not been attained by conventional methods, eliminates purification of the primary antibody, and enables one to save the amount of immobilized antibody. In addition, it provides a measuring method which is inexpensive and yet effective and which can determine a trace amount of ingredient with high sensitivity.