PA-TagRFP is a photoactivatable mutant of the bright monomeric red fluorescent protein TagRFP [Subach et al., 2010]. PA-TagRFP is capable of irreversible photoconversion from non-fluorescent to red fluorescent form (with excitation/emission maxima at 562 nm and 595 nm, respectively) in response to UV-violet light irradiation.

High brightness, photostability and monomeric nature of PA-TagRFP make it an excellent protein tag for both conventional microscopy and super-resolution PALM imaging techniques [Subach et al., 2010].