Title :
Two-photon fluorescent labels with enhanced sensitivity for biological imaging
Author :
Wenseleers, Wim ; Stellacci, Francesco ; Pond, Stephanie ; Parker, Timothy ; Mangel, Timo ; Halik, Marcus ; Meyer-Friedrichsen, Timo ; Perry, Joseph W. ; Marder, Seth R. ; Heikal, Ahmed A. ; Huang, Shaohui ; Webb, Watt W.
Author_Institution :
Dept. of Chem., Arizona Univ., Tucson, AZ, USA
Abstract :
The development of two-photon laser scanning fluorescence microscopy (TPLSM) has provided a new capability for 3D imaging in whole and living tissues, reduced photobleaching effects, and greater depth penetration. Since the rate of two-photon excitation is proportional to the square of the light intensity, degree of excitation falls off roughly as the fourth power of distance from the focal plane. The full potential of two-photon fluorescence microscopy has not been realized, in part, because fluorophores under use have been developed for single photon excitation and have not been optimized for two-photon absorption. Highly efficient two-photon fluorophores are needed to allow sensitive detection of small numbers of labeled sites and to reduce the optical power of the exciting laser beam that is needed to produce adequate signal levels. The sensitivity of a two-photon fluorescence label is determined by the product of the two-photon absorption cross section and the fluorescence quantum efficiency
Keywords :
biological techniques; biomedical imaging; fluorescence; laser applications in medicine; optical microscopy; optical saturable absorption; two-photon spectroscopy; biological imaging; depth penetration; exciting laser beam; fluorescence quantum efficiency; focal plane; highly efficient two-photon fluorophores; labeled sites; living tissues; optical power; photobleaching effects; sensitivity; signal levels; three dimensional imaging; two-photon absorption cross section; two-photon excitation; two-photon fluorescence label; two-photon fluorescent labels; two-photon laser scanning fluorescence microscopy; whole tissues; Absorption; Biological systems; Biomedical optical imaging; Charge transfer; Fluorescence; Laser excitation; Microscopy; Optical imaging; Optical sensors; Solvents;
Conference_Titel :
Lasers and Electro-Optics Society 2000 Annual Meeting. LEOS 2000. 13th Annual Meeting. IEEE
Conference_Location :
Rio Grande
Print_ISBN :
0-7803-5947-X
DOI :
10.1109/LEOS.2000.890812