<Emphasis Type="Italic">In vitro</Emphasis> Relationship of SV40 Tumour-specific Surface Antigen to other SV40 Antigens

WE have previously described a rapid and quantitative cytotoxic assay in which target cells labelled with⁵¹Cr are used to identify a tumour-specific surface (TSS) antigen expressed by different lines of mouse cells transformed by SV40. We have now investigated the relationship between the activity of this antigen and the virus-specific surface (S) antigen, associated with SV40 transformed hamster cells².