Confocal fluorescence lifetime imaging of free calcium in single cells.
Ca(2+) concentrations in biological cells are widely studied with fluorescent probes. The probes have a high selectivity for free calcium and exhibit marked changes in their photophysical properties upon binding. The differences in the fluorescent lifetime of the probes can now be used as a contrast mechanism for imaging purposes. This technique can be further exploited for the quantitative determination of ion concentrations within the cells. We describe the use of a fast fluorescence lifetime imaging method in combination with a standard confocal laser scanning microscope for the determination of Ca(2+) concentrations in single rat cardiac myocytes using the intensity probe Calcium Green.
Department of Molecular Biophysics, Utrecht University, Buys Ballot Laboratory, P.O. Box 80.000, 3508 TA, Utrecht, The Netherlands.
R
R
Sanders
H C
HC
Gerritsen
A
A
Draaijer
P M
PM
Houpt
Y K
YK
Levine