Comparative studies of mouse tumors with respect to their capacity for growth as "ascites tumors" and their average nucleic acid content per cell

The advantages presented by the use of the comparatively homogeneous free tumor cell suspension of the Ehrlich ascites tumor for quantitative studies on the growth and chemical composition of tumor cells and for chemotherapeutic experiments have led to the present investigation of a representative array of 26 histologically and genetically different mouse tumors which were tested for their capacity of reaching a condition similar to the Ehrlich ascites tumor. This has been found to be possible in a number of cases. Dissociated solid tumor masses were intraperitoneally inoculated into the corresponding mouse strain. Tumor growth on the peritoneum, accompanied by exudate formation, resulted in 22 out of 26 cases. The resulting exudates, which, in the case of all carcinomas and most sarcomas tested, contained very few tumor cells, transmitted the tumors upon further intraperitoneal injection in 18 instances. The tumors which developed were now regularly provoking exudate formation, and on subsequent generations the exudates have always been transplanted intraperitoneally. In the case of all carcinomas and in 2 out of 3 sarcomas tested which have passed over 10 such "fluid transplant generations" (FTG), a gradual increase in the frequency of tumor cells in the ascitic fluids (examined around median survival time) was occurring after a certain.