Experimental investigations on fluorescence excitation and depletion of ATTO 390 dye

Abstract

A novel fluorescent dye named ATTO 390 is tested and verified to be applicable in STED microscopy with great performance. The experimental configuration uses a 405nm continuous wave (CW) laser as excitation beam and a 532nm CW laser as depletion beam. The two collinear beams are focused on the dye using an objective with NA=1.4 and the fluorescence is detected by avalanche photodiode detector. With short wavelength in violet band, high fluorescence quantum yield, good photostability, and relatively low Ps demonstrated in a series of experiments, ATTO 390 is proved to be a potential good choice for fluorescent dye in STED microscopy.