UC Irvine

Optical laser trapping microscopy has emerged as a powerful tool not only for the optical manipulation of cells and macromolecules, but also for the study of cellular physiological responses via force transduction and fluorescence imaging. We describe here the most recent results from our laboratory in the use and application of laser trapping microscopy to a variety of studies at the cellular and molecular levels. Fluorescence spectroscopy and imaging have been successfully combined with optical micromanipulation. A single near-infrared laser beam is used for two-photon fluorescence excitation and micromanipulation of trapped biological specimens. Cell viability is observed and monitored with a Nd:YAG laser ((lambda) equals 1064 nm) and an Al:GaAs diode laser ((lambda) equals 809 nm). Traps and conventional fluorescence imaging are also used simultaneously to examine T-cell activation dynamics. ©2004 Copyright SPIE - The International Society for Optical Engineering.