Bioassay of blood-born tumour cells on in vivo and in vitro systems.

Viability and biological integrity of tumour cells circulating in the blood were studied in an experimental system using bioassay methods. Results of subcutaneous and intravenous retransplantation as well as explantation of the blood obtained from tumour-bearing animals previously receiving intravenous inoculation of tumour cell suspension (Yoshida sarcoma, Walker 256 carcinosarcoma and DMBA-induced myeloid ascitic leukaemia), revealed that the tumour cells detected in the blood are not only viable at the time of their transportation in the blood-stream but are also in possession of biologic potentials to proliferate and establish metastatic growths in organs.