Using light-producing molecules to observe cellular events is standard fare in many a lab, but it’s only recently that scientists have begun to harness the power of light to manipulate biological systems experimentally. By rigging a cell or protein with a light-sensing molecule, it’s now possible to alter cellular biochemistry or neural action potentials with the flash of a laser.
Tweaking a cell or organism with gene knockouts, small molecule inhibitors, or RNA interference leaves it time to compensate, potentially muddying results. But a light signal takes effect instantaneously, providing unprecedented temporal and spatial precision. Just as green fluorescent protein revolutionized cell biology by tracking light output, “these genetically encoded photoswitches will raise perturbation to that same level,” says Michael Rosen of the University of Texas Southwestern Medical Center in Dallas.
But photoswitches require finesse: to adapt nature’s light sensors for your own use, you’ll likely have to optimize factors ...
