Multiple copies of identical epitopes on the adenovirus hexon

Abstract A double monoclonal antibody (MAb) sandwich enzyme-linked immunosorbent assay (double MAb ELISA), which uses the same MAb as solid-phase immunosorbent (capture MAb) and as detector MAb (peroxidase-labeled), was developed to quantify the specific epitopes of adenovirus hexon. Four MAbs directed against crystallized adenovirus type 1 (Ad h 1) hexon were tested by this assay with homologous and different heterologous hexons. The lowest reacting concn with the homologous and heterologous hexon types both in direct and double MAb ELISA was determined and compared. At least two copies of four different epitopes were identified by the MAbs. Evidence is presented that more than one copy of identical or closely related epitopes exist on the homologous as well as on the heterologous hexon molecules. However, their presence could be detected only in higher concn of hexon preparations of subgenera A, B and D.