Modification of the Action of Ionizing Irradiation on Escherichia coli by 2-Fluoroadenosine

Abstract

IN the course of routine screening for radiation modifiers in bacterial systems, 2-fluoroadenosine¹ has been observed to modify the activity of ionizing irradiation on non-proliferating Escherichia coli. The procedures used to determine irradiation-modifying activity have been described². In essence, the procedure used for measuring effects on non-growing cells consists of exposing washed cells (grown on simple glucose-salts medium and resuspended in M/1.5 phosphate buffer) to irradiation from a cobalt-60 source (∼ 1,000 c., dose rate of 2.0 kr./min) with and without test compound. Experiments with growing cells were performed in which the test compound was added to the glucose-salts medium at the time of inoculation and aliquots of cell suspensions irradiated at varying times during the growth cycle.