NEW TIME-RESOLVED TECHIQUES IN 2-PHOTON MICROSCOPY

Microscopy is traditionally a tool for determining biological structur es. Many recent advances in optical microscopy involves the incorporat ion of spectroscopy techniques to monitor biochemical states of micros copic structures in living cells and tissues. By minimizing tissue pho todamage, two-photon excitation microscopy provides a new opportunity to study the dynamics of biological systems on time scales from nanose conds to hours. This review will focus on a number of these new method s: two-photon time-lapse microscopy, two-photon photoactivation, two-p hoton correlated spectroscopy, two-photon single particle tracking and two-photon lifetime microscopy.