Immunological studies of the group B coxsackieviruses by the sandwich enzyme-linked immunosorbent assay (ELISA) and immunoprecipitation.

A microplate double antibody sandwich ELISA was employed in an immunological study of the group B Coxsackieviruses. The assay, described in detail, detected high dilutions of virion antigen (less than 10 ng) in purified preparations and in crude infected cell extracts. Furthermore, by using a constant amount of antigen, group B virus antibodies in hamster antisera could be quantified with a sensitivity equivalent to the virus neutralization test. Titrations of virus antigens and antibodies were found to be type-specific when purified virions were employed in the assay. Urea disruption of virions exposed antigens common to all six group B viruses. The heterotypic reactivity of disrupted group B virions did not extend to the other viruses tested. Immunoprecipitation and SDS-PAGE analysis revealed that, of the four virion structural polypeptides (VPI to 4), VPI contained the major common antigenic determinants shared by members of the group B Coxsackieviruses.