REU Student: David Leichtman, Mentor: William Cooke

Optical tweezers, known as laser tweezers, use the method of optical trapping by a focused light beam to hold samples in place on a microscope stage. Optical trapping in 3 dimensions is achieved by focusing an optical beam to a point within, or just outside, a highly transmitting sample in solution. Focusing is accomplished by the objective lens of a common microscope. The sample is then held in place while the microscope stage is moved around it. This method is of great use in biological microscopy in that it allows samples to be manipulated without being touched.