Attenuation of photobleaching in two-photon excitation fluorescence from green fluorescent protein with shaped excitation pulses
Kawano, H × Nabekawa, Y Suda, A Oishi, Y Mizuno, Hideaki Miyawaki, A Midorikawa, K #
Biochemical and Biophysical Research Communications vol:311 issue:3 pages:592-596
The two-photon excitation fluorescence (TPEF) process of an enhanced green fluorescent protein (EGFP) for fluorescence signals was adaptively controlled by the phase-modulation of femtosecond pulses. After the iteration of pulse shaping, a twofold increase in the ratio of the fluorescence signal to the laser peak power was achieved. Compared with conventional pulses optimized for peak power, phase-optimized laser pulses reduced the bleaching rate of EGFP by a factor of 4 while maintaining the same intensity of the fluorescence signal. Our method will provide a powerful solution to various problems confronting researchers, such as the photobleaching of dyes in two-photon excitation microscopy. (C) 2003 Elsevier Inc. All rights reserved.