Behaviour of murine lymphosarcoma cells during prolonged cultivation in vivo

Transplantable strain of murine lymphosarcoma growing as a free suspension in the peritoneal cavity of isologous hosts was isolated after fractionated irradiation of C57BL mice. A 14-year cultivation led to changes in its properties; the mean survival time of the hosts was shortened, the modal number of chromosomes changed from 41--42 to 39 and their radioresistance increased slightly. Strain specificity remained unchanged.