Search for Virus in Human Leukemia: Effects of Nucleic Acids Extracted From Leukemic Tis- sues on Cell Culture 1. 2

Nucleic acids, extracted by the phenol Ulethod froUl 18 norUlal tissues and 56 leukeUlic tissues, were inoculated into cell cultures of hUUlan aUlnion, hUUlan fetal skin Uluscle and kidney, hUUlan bone Ulanow, and Ulonkey kidney. No reproducible cytopathic or trans-fOrnling effects were observed in the inoculated cultures. Control studies with infectious poliovirus ribonucleic acid (RNA) suggested that the optimal conditions for cell infection used in these experiUlents and the cell nUUlbers extracted should have allowed detec-tion if each cell had contained one in-fectious RNA Ulolccule per cell and if such a Ulolecule produced a clone of transforUled cells or a cytologic change. The negative results obtained would appear significant if the hypothetical hUUlan leukeUlia viruses were RNA-containing viruses. Sinlilar control studies with infectious deoxyribo-nucleic acid (DNA) extracted froUl SV40 indicated that an infectious DNA would have been Uluch Ulore difficult to detect. Such results Ulay be inter-preted as a failure of the Ulethods eUl-ployed, rather than as evidence against the possible viral etiology of hUUla