| abstract |
A method and reagent kit means are provided for assay of a selected antigen such as hCG or CEA in an aliquot of body fluid. The method comprises the steps of constituting the aliquot in a mixture comprising tracer (which may be an enzyme tracer or a radioactive tracer) conjugated with monoclonal antibody, and separate immobilized monoclonal antibody, incubating the mixture to enable separation of a solid phase antigen antibody conjugate in sandwich relation, and measuring the tracer content and corresponding antigen content of the aqueous phase or the solid phase. The antibody (conjugated and/or immobilized) comprises multiple monoclonal antibodies from different cell lines so that the specificity of the assay is enhanced, and the possibility of unrecognized antigen fragments is reduced. Also, as a preferred option, the incubation may be carried out with a scavenger monoclonal antibody so that, as an example, in the context of hCG assay, the scavenger chosen for beta subunit selectivity but low hCG affinity is present in the reaction to prevent any possible cross reactivity from analogs of homologous reactivity. |