A cellular laser

A living laser developed from a cell that expresses green fluorescent protein is published online this week in Nature Photonics. The laser could potentially be useful in the development of new forms of biological imaging, sensing and cytometry, although applications are mostly speculative at this early stage.

All lasers require an optical gain medium to function. Conventionally, these are made from inanimate substances such as doped crystals, semiconductors, liquid dyes or gases. Malte Gather and Seok Hyun Yun created their biological gain medium by placing a single cell into a specially designed highly reflective microcavity. When fed with pulses of blue light, the cell emits a bright, directional beam of green laser light.

Such an organic gain medium not only has the potential to reproduce and heal itself, but is also inherently biocompatible.