Objective: To study DNA double-strand breaks of human peripheral lymphocytes exposed to lead with flow cytometry (FCM).
Methods: The lymphocytes were obtained from 36 workers occupationally exposed to lead and 70 residents without occupational exposure to lead. DNA double-strand breaks were detected by flow cytometer assay. The lymphocytes from health people were incubated with lead at different doses and time, FCM assay was used to detect DNA double-strand breaks.
Results: DNA double-strand breaks and fluorescence intensity of high exposed group and low exposed group were 41.76% ± 28.57%, 9.90 ± 3.35 and 33.18% ± 30.64%, 9.39 ± 4.83, respectively, which were significantly higher than those (0.28% ± 0.28% and 6.95 ± 2.93) of control group (P<0.05). The results of in vitro experiment indicated that DNA double-strand breaks of lymphocytes exposed to Pb at the dose of 125.0, 250.0, 500.0 µmol/L for 1 and 2 h were significantly different from those of the negative control group and positive control group (P<0.01). DNA double-strand breaks increased at beginning and then decreased with lead doses.
Conclusion: Lead can induce DNA double-strand breaks, γH2AX detected using flow cytometer assay can be used to measure the DSBs of DNA in large samples.