The aim of this research was to study photobehavior of a popular blue fluorescent protein TagBFP and apply this marker for super-resolution microscopy. Materials and Methods. Photoactivation of TagBFP was examined both in protein solution in vitro and in living cells. Subdiffraction imaging was performed using total internal reflection fluorescence microscopy followed by super-resolution radial fluctuations or single-molecule localization analysis. Results. We show that TagBFP exhibits blinking behavior upon 405 nm light illumination. Moreover, photoactivation to red-emitting state is occurring in the conditions typically used for TagBFP imaging. The red (photoactivated) form of TagBFP possesses spectral properties similar to TagRFP — a close homologue of TagBFP. We show that both blinking and photoactivation of TagBFP can be utilized for super-resolution imaging. We conclude that photoactivation of TagBFP to red-emitting form should be taken into account in the design of multi-channel imaging experiments involving high-power or prolonged UV illumination.
- Blue-to-red photoconversion
- Super-resolution microscopy