Tumours in the Rat after Injection of Preneoplastic and Neoplastic Nucleic Acids

SOME years ago, it was reported from our laboratories that lymphosarcomas developed at the site of subcutaneous injection of a chromatin fraction obtained from Murphy lymphosarcoma cells, and that hepatomas appeared at the site of intrahepatic injection of a similar fraction obtained from cells of a transplantable hepatoma 1–3 . The significance of these observations was questioned on the grounds that the possibility of the presence of intact cells in the injected material could not be excluded with certainty.