Abstract: A heterogeneous specific binding assay method and test means for the simultaneous determination of each of a plurality of different ligands (e.g., antibodies, antigens or haptens) in a single liquid test sample. The assay may follow any conventional technique of a heterogeneous type, i.e., which includes a separation of a bound-species from a free-species form of the labeled reagent. The combined assay is accomplished by using solid-phase binding agents for the respective ligands to be determined which are differentially separable from each other, thereby permitting the use of a single label rather than a different label for each ligand to be determined. The assay is particularly suited to the simultaneous determination of different antibodies, particularly antibodies to different viral antigens, in a single serum sample.