Abstract
Five of five human teratocarcinomas cultured in vitro could be induced to synthesize retrovirus-like particles, albeit in extremely low amounts. The accumulation and purification of the human teratocarcinoma-derived retrovirus (HTDV) from one of these cell lines allowed characterization of its genomic material as high mol. wt. (60S) RNA. Partial purification of HTDV-associated RNA-dependent DNA polymerase (reverse transcriptase) has also been achieved. HTDVs are easily distinguishable from the exogenous human T-lymphotropic viruses and human immunodeficiency viruses by morphological, biological and immunological criteria.