[The examination of DNA strand breaks induced by peplomycin-using non-radioactive in situ nick translation method]

In situ nick translation (ISNT) is a method to detect DNA single strand break (nick) at each cellular level. In this study, peplomycin (PEP)-induced DNA strand breaks and its repair were examined using non-radioactive ISNT method. Human fibroblasts were cultured with various concentrations of PEP for different durations, and then DNA strand breaks were evaluated by ISNT method. The signal intensity of DNA strand breaks of the PEP-treated fibroblasts was increased in a dose dependent manner. At the fixed concentration of PEP, it reached to a maximum level after 10 min. of culture and remained unchanged for at least 24 hours. In addition, DNA strand breaks induced by PEP was rapidly repaired in 10 min. after washing. Thus, the non-radioactive ISNT is thought to be a quick, sensitive and specific method not only to detect DNA strand breaks but also to observe its repair.