An immunological method for the detection of an antigen specific antibody comprising one or more of the immunoglobulin classes A, M, D, or E in a fluid, comprising the simultaneous incubation of:
- a. a solid phase having bonded thereto an antibody specific for said immunoglobulin classes A, M, D, or E;
- b. a fluid containing an immunoglobulin of classes A, M, D, or E;
- c. an unlabeled antigen immunologically reactive to the fluid phase immunoglobulin;
- d. a labeled antibody, immunologically reactive with said unlabeled antigen;
- and
- e. a substance which inhibits the binding of immunoglobulin G to the solid phase and which inhibits the binding of said unlabeled antigen to immunoglobulin G.