[The use of an immunohistochemical method for detecting N7-methylguanine in human cells].

An immunohistochemical method, followed by silvering (Ag-treatment) of the final product of peroxidase reaction for N7-methylguanine detection, was first employed for human cells treated in vitro with N-methylnitrosourea. This method appeared to be highly specific and sensitive, compared to the routine immunohistochemical technique. Evidence has been provided on the application of Ag-treatment for detecting N7-methylguanine in the esophagus epithelium of patients with a high risk of cancer with this particular locality.