fibroblasts from xenopus laevis , which possess photoreactivating enzyme were used to study the influence of photoreactivating light on the frequency of pyrimidine dimers in dna , chromosomal aberrations , sister chromatid exchanges , cell killing and the induction of gene mutations ( ouabain-resistance ) induced by 254 nm ultraviolet irradiation .
C0037211
sister chromatid exchanges
C0007634
cell