Fluorescence Recovery after Photo-bleaching Apparatus Using Second Harmonic of 1120 nm Semiconductor Laser for Illumination

Abstract

A compact fluorescence recovery after photo-bleaching (FRAP) apparatus was constructed using a semiconductor laser as an illumination light source. The second harmonic, 560 nm, of the 1120 nm semiconductor laser is guided to the light source point of the fluorescence microscope by an optical fiber. Since the illumination light wavelength 560 nm almost fits to the absorption maximum of the fluorescence dye molecule rhodamine B sulfonyl, the photo-bleaching was induced efficiently with minimum heating of the microscope lens system. The time dependence of the fluorescence recovery was directly measured by the photo-multiplier attached and the diffusion coefficient of the lipid molecules was calculated. [DOI: 10.1380/ejssnt.2005.254]