Combination of TUNEL Assay with Immunohistochemistry for Simultaneous Detection of DNA Fragmentation and Oxidative Cell Damage

Oxidative cell damage causes disruption of DNA via formation of 8-hydroxy-2′-deoxyguanosine and can trigger apoptotic cell death. The cells damaged by oxidative stress can either become apoptotic, or recover. Therefore, it is helpful to employ a parallel assay that would confirm whether cells experiencing oxidative damage undergo apoptosis. Our paper describes the technique that combines immunohistochemical detection of 8-hydroxy-2′-deoxyguanosine with the TUNEL assay. This permits simultaneous detection of oxidative damage and apoptosis at a single-cell level. We have developed simple and reliable protocols which can be used with cultured cells and slide-mounted tissue sections. These techniques can be employed in research dealing with high-throughput drug screening, toxicology, and cancer.