Conversion of the inconvertible L-1 lymphosarcoma to ascitic form.

Abstract

DURING the course of experiments with the L-I lymphosarcoma it was often desirable to have large numbers of single cells available. Suspensions of cells dissociated from minced tumour by standard techniques (cytosieve1, trypsinization2, etc.) contained variable numbers of morphologically dead cells and required large inocula (≫104 cells) to induce growth on subcutaneous re-inoculation. It seemed that the required numbers of free cells might be obtained if the tumour was converted to ascitic form. Following the method described by Klein and Klein3, cell suspensions prepared from the tumour by various techniques were intraperitoneally injected into strain A/J hosts. At graded intervals afterwards, the mice were killed, the open peritoneal cavity washed, and the collected washing re-inoculated into new mice. This was repeated for several fluid-transfer generations. In a course of more than twenty-five such attempts, a small growth of ascites was obtained in. only a single instance. This one ascites grew slowly for three fluid-transfer generations and then failed to multiply on the fourth re-inoculation. In all other attempts, this procedure failed to produce ascitic growth. In many animals, however, nodular growths were obtained at the site of injection of the initial suspension, or on the peritoneal surface.