Preparation of highly purified human cytomegalovirus envelope antigen.

A human cytomegalovirus (HCMV) envelope preparation was highly purified by immunoaffinity column chromatography using an anti-cellular-IgG column. The purified envelope induced high titre antibodies to HCMV in guinea-pigs. Analysis of the guinea-pig immune sera by RIA and immunofluorescence (IF) showed that this envelope preparation, unlike its unpurified counterpart, did not induce antibody to cellular contaminants. Dot-blot assay revealed viral proteins in the flow-through fraction and cellular proteins in the bound fractions. Results of sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of flow-through and bound fractions suggest that a number of proteins previously identified as virus-specific may, in fact, reflect cellular contamination of the envelope preparation, or crossreactivity of some virus-specific proteins with cellular proteins.