A simple and rapid mix-and-read assay for sensitive detection of O 6 -methylguanine DNA methyltransferase.

We have developed a simple and rapid mix-and-read assay for the sensitive detection of O 6 -methylguanine DNA methyltransferase (MGMT) activity based on exonuclease III-assisted signal amplification under completely isothermal conditions (37 °C). This method is very simple and rapid (60 min) with ultrahigh sensitivity and good specificity, and it can detect MGMT activity at the single-cell level. Moreover, this method can be applied for the screening of MGMT inhibitors and the discrimination of MGMT in different cancer cells.