Improved Fluorescent Protein Contrast and Discrimination by Optically Controlling Dark State Lifetimes.

ABSTRACT: Modulation and optical control of photoswitchable fluorescent protein (PS-FP) dark state lifetimes drastically improves sensitivity and selectivity in fluorescence imaging. The dark state population of PS-FPs generates an out-of-phase fluorescence component relative to the sinusoidally modulated 488 nm laser excitation. Because this apparent phase advanced emission results from slow recovery to the fluorescent manifold, we hasten recovery and, therefore, modulation frequency by varying coillumination intensity at 405 nm. As 405 nm illumination regenerates the fluorescent ground state more rapidly than via thermal recovery, we experimentally demonstrate that secondary illumination can control PS-FPs dark state lifetime to act as an additional dimension for discriminating spatially and spect

SUBMITTER: Chen YC 

PROVIDER: S-EPMC5313373 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature