Quantification of cell death in human fibroblasts by measuring the loss of [ 14C]thymidine from prelabeled cell monolayers

Abstract

The loss of [ 14C]thymidine from prelabeled cell monolayers may be used to estimate cell death in proliferating cultured fibroblasts. Reuptake of 14C from labeled DNA or DNA products of dead cells is minimal and may be further reduced by the addition of unlabeled thymidine (10 4 m). Excision repair processes do not contribute to reincorporation of isotope. In cells exposed to adverse experimental conditions, slight differences in the quantification of cell death by this method and exclusion of erythrosin B occurred. Spontaneous loss of 14C from the cell layer does not occur, so this approach allows an assessment of cell death over a longer time period than is possible with other radiolabeling techniques (e.g., 51Cr).