Summary
Radiosensitization by misonidazole of hypoxic mammalian cells in dilute suspension is modified by the presence of the stable free radical, TAN. The dose modifying factor (DMF) of 15 mM misonidazole is 2·4 for cell inactivation, and 3·5 for the production of single-strand breaks in DNA. The presence of TAN decreases these values to 1·5 and 1·75 respectively. Possible explanations for these observations are discussed. The DMF of misonidazole for cells in pellet is not affected by TAN.