2-aminopurine(2-AP) is an analogue of the DNA base adenine (6-aminopurine). 2-AP
is intensely fluorescent compared with adenine and as such is widely used as a probe of DNA conformation and dynamics, where 2-AP is used to replaces a base in the DNA helix. The fluorescence lifetime(s) of 2-AP in DNA can be used to obtain information on the immediate environment of the probe. In this way, information about the interaction of DNA with proteins and the motions of DNA can be acquired.