A sensitive alkali-unwinding assay was used to measure DNA strand breakage in Chinese hamster V79 cells caused by low-level incorporation of methyl-labelled [3H] and [14C] thymidine, and to estimate the effective dose per disintegration relative to low doses of gamma-irradiation. Damage equivalent to 0·0035 ± 0·0006 and 0·0014 ± 0·0005 Gy was observed for each 3H and 14C disintegration respectively. These values agree well with those expected from the estimated nuclear radiation dose delivered by the beta particles if a relative biological effect (r.b.e.) of 1·0 is assumed, and suggest that strand-breakage produced by these isotopes is determined by the nuclear radiation dose delivered by the beta particles.
- Beta particles
- DNA damage
- Low doses
- Strand breaks
ASJC Scopus subject areas
- Radiological and Ultrasound Technology
- Radiology Nuclear Medicine and imaging