Recovery from potentially lethal damage following irradiation with x-rays or cyclotron neutrons. I. Response of EMT-6 cells in vitro

Cultured EMT-6 cells, in a nutritionally limited plateau stage of growth, were used to study recovery from potentially lethal radiation damage. If subculture was delayed after irradiation with x rays or cyclotron neutrons, recovery from potentially lethal damage was seen as an increase in survival relative to that in cells subcultured immediately after irradiation. The time course of damage repair seemed to be similar after both types of radiation; the extent of recovery, while variable, can be large after the high linear energy transfer (LET) exposure as well as after photon radiation. When parallel x ray and neutron experiments were performed with the same culture passage, the amount of post-neutron repair was less than that occurring after x irradiation