Scientists Can Turn Human Cells Into Working Lasers

The team detailed the process in a paper published in Nature Photonics. For these microlasers, the spectrum is more narrow, in the 500-800 nanometre range, making it easier to label cells with light, says Jeffrey Karp, a bioengineer at Brigham and Women’s Hospital in Boston, Massachusetts. For the current study, Yun and Humar used tiny spherical objects capable of confining light by reflection from their inner surfaces as microcavities for the amplification of laser light within the cavity. In one example, they injected oil into human cells-“almost any cell” will work, Humar tells Quartz-and filled the oil droplets with fluorescent dye.

Secondly, the team used polystyrene beads, which were ingested by a type of white blood cell, to carry out functions similar to the oil droplets.

The lipid droplet (orange) within a fat cell can be used as a natural laser. While at first it might seem as practical as attaching lasers to sharks’ heads, the technology actually has great potential in biomedical applications for tracking individual cell movements within a living body. When the fluorescent molecules are excited, a sphere rings with light of specific wavelengths, just as an organ pipe rings with sound at a fundamental frequency and its overtones.

The finding could make for significant improvements in cell imaging, used frequently in research on cancer and infectious diseases.

Currently, fluorescent dyes are often used to tag living cells and emit light.

The new method of turning cells into tiny lasers makes it much easier to distinguish between tagged cells since lasers have a more narrow range of wavelengths.

Because this laser light has optical characteristics that are unique to the cell that the microresonator finds itself in, all the cells tagged this way can be tracked individually for days at a time as they migrate throughout the body. “Imagine rather than a biopsy for a lump that doctors suspect to be cancer, cell lasers helping determine what it’s made of”. As New Scientist reported, a group at the University of St. Andrews in the UK has also worked with using macrophages to create intracellular lasers.