[Growth activity and radiosensitivity of Pliss lymphosarcoma cells fractionated by sedimentation]

The sedimentation fractionation of ascitic form of Plyss lymphosarcoma was performed in the linear 1-3% sucrose gradient with 1 g. Fractions were different in cell sizes, protein content and also in intensity of the 3H-thymidine incorporation. Fractions which contained cells in the G1, G1 + S and S + G2 phases were transplanted in vivo in a solid form. Cells with the low sedimentation rate had the maximum growth capacity. The growth rate of G1 + S cells was similar to that of the initial tumour. Cells of high-rate sedimentation were characterized by the low growth activity. The values of D0 for these 3 fractions were 1.64, 2.05 and 2.11 Gy, and those of n 1.9, 2.9 and 1.6, respectively. These differences were not a result of selective injury of cells in fractions or their contamination by nontumour cells.