Repair of gamma-ray induced single-strand breaks in human lymphocytes

Human peripheral blood lymphocytes are one of the most radiosensitive mammalian cells. We tested whether this radiosensitivity was associated with the persistance of unrepaired DNA damage in gamma-irradiated lymphocytes. Repair was determined by measuring the loss and recovery of DNA supercoiling when nucleoids are centrifuged in the presence of increasing amounts of ethidium bromide. Results show a limited repair capacity in resting human lymphocytes after gamma-irradiation.