Optical Trapping and Manipulation of Single Cells Using Infra- Red Laser Beams.

Use of optical traps for the manipulation of biological particles was recently proposed, and initial observations of laser trapping of bacteria and viruses were reported with visible argon laser light. We report here the use of infra-red (IR) light at 1. 06microns to make much improved laser traps with significantly less optical damage to a variety of live cells. With IR light we have observed reproduction of E. coli bacteria within optical traps at power levels sufficient to give manipulation at velocities up to about 500microns/sec. Reproduction of yeast cells by budding was also achieved in IR traps capable of manipulating single cells and clumps of cells at velocities of about 100microns/sec.