Immunochemical method and reagent for the determination of a polyvalent antigen in a fluid probe.

摘要

The present invention provides a process for the quantitative determination of a polyvalent antigen by incubation with three different receptors of which the first (R1) and the third (R3) are present in liquid phase and are bindable with the antigen, the second receptor (R2) is present in solid phase and is bindable with receptor (R1), and receptor (R3) carries a label and does not cross-react with (R1) and (R2), separation of the solid phase from the liquid phase and measurement of the label in one of the phases, wherein a first receptor (R1) is used which consists of at least two antibody molecules or antibody molecule fragments bound with one another, at least one of which binds specifically with the antigen to be determined. The present invention also provides a reagent for the quantitative determination of a polyvalent antigen containing three receptors (R1, R2 and R3) of which (R1) and (R3) are soluble and bindable with the antigen, (R3) is labelled and does not cross-react with (R1) and (R2), wherein (R1) consists of at least two antibody molecules or antibody molecule fragments bound with one another, at least one of which binds specifically with the antigen to be determined.