title: The study of cells by optical trapping and manipulation of living cells using infrared laser beams.
abstract: The new technique of optical trapping and manipulation of living cells using the forces of radiation pressure from infrared single beam gradient laser traps is reviewed.  These traps, also referred to as "optical tweezers," are capable of stably trapping transparent micron and submicron biological particles free of optical damage.  Entire cells or organelles within the interior of living cells can be manipulated without damaging the cell wall.  The trap is built into a high resolution microscope for combined trapping and high resolution viewing.  Experiments demonstrating reproduction of motile bacteria and yeast cells within infrared traps and manipulations of plant and animal cells are discussed.  Applications to the study of the mechanical properties of cell cytoplasm, study of cell function, and cell separation and orientation are considered.  The ability to apply controlled light forces on cells of magnitude comparable to or often much greater than gravity suggests that these optical techniques might have relevance to experiments showing the influence of gravity on cells.
authors.affiliation: AT&T Bell Laboratories, Holmdel, NJ 07733.
authors.forename: A
authors.initials: A
authors.lastname: Ashkin
mesh_terms: D055592:Biophysical Phenomena; D001703:Biophysics; D002477:Cells / Q000528:radiation effects* / Q000648:ultrastructure; D003584:Cytological Techniques; D006112:Gravitation; D007259:Infrared Rays; D007834:Lasers; D008853:Microscopy; D055095:Optics and Photonics / Q000295:instrumentation; D015388:Organelles