Heavy-Ion Irradiation of Human and Chinese Hamster Cells in Vitro

Cultured human kidney (T-1) and liver (Chang) cells and Chinese hamster bone marrow (M3-1) cells were irradiated with heavy ions from the Berkeley heavy-ion linear accelerator, and their subsequent ability to grow into visible colonies was assessed. Heavy-ion inactivation cross sections were compared to microscopically measured nuclear cross section distributions found in cultures under the conditions of irradiation. Chinese hamster cells were found more resistant to all radiations studied within the linear energy-transfer range of 45-20,000 MeV- cm²/ g and this higher resistance relative to the human cells appeared to correlate with the smaller nuclear cross-sectional area of the Chinese hamster cells.