Multiepitopic immunometric assay

An immunometric assay for a multivalent antigen in a sample, comprising:

• (a) forming a mixture of said sample with multiple immobilized monoclonal antibodies against different epitopes on said antigen, and incubating said mixture for a time and under conditions sufficient to allow said antigen in said sample to bind to said multiple immobilized monoclonal antibodies;
• (b) adding to said mixture after said incubation of step (a) a detectably labeled monoclonal soluble antibody which is identical to one of said multiple immobilized monoclonal antibodies, and incubating the new resulting mixture for a time and under conditions sufficient to allow said detectably labeled monoclonal soluble antibody to bind to said antigen;
• (c) separating detectably labeled monoclonal antibody bound to said antigen from detectably labeled monoclonal soluble antibody;
• and
• (d) detecting either said detectably labeled monoclonal antibody bound to said antigen, or detecting detectably labeled monoclonal soluble antibody not bound to said antigen;
• wherein any one of said multiple immobilized monoclonal antibodies shows, by itself, substantially less binding towards said antigen in said immunometric assay, when used with itself or another monoclonal antibody in soluble labeled form, than when used with multiple immobilized monoclonal antibodies in combination.