Adenine DNA glycosylase, also known as mutY, is an adenine DNA glycosylase active on DNA substrates containing A/G, A/8-oxoG, or A/C mismatches and also has a weak guanine glycosylase activity on G/8-oxoG-containing DNA. mutY is crucial for the avoidance of mutations resulting from oxidative DNA damage. Increasing levels of mutY in A549 cells exposed to oxygen and infrared radiation leads to improvements in cell survival. It is abundant in neurons where mitochondrial genomes exposed to reactive oxygen species (ROS) that damage DNA must maintain integrity over the entire mammalian life span. Recombinant E.coil mutY protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.