Hydroxyl radical footprinting of fluorescently labeled DNA

Footprinting is one of the simplest and most accurate approaches to investigate structure and interaction of biopolymers. It is based on the more difficult accessibility of intra- and intermolecular contacts for external damaging agents. According to this method, one end of polymer molecules is labeled before a sample is incubated with a damaging agent. The distribution of split products is used to conclude on the accessibility of different polymer regions under specific conditions. A variety of enzymatic and chemical splitting agents are used for footprinting. Currently, the highest temporal and spatial resolution without profound specificity to a nucleotide sequence can be reached with the use of hydroxyl radicals. A new variant of this approach, which suggests the use of DNA fluorescent labeling together with the present-day quantitative analysis, will allow extending the method’s boundaries.