Intracellular Microlasers

Synopsis

Two groups of researchers have independently developed micron-sized lasers within living cells. One group introduced plastic microspheres, loaded with synthetic dye, into individual cells via a natural process known as endocytosis. Upon excitation, the microspheres resonate with wavelengths dependent on the sphere size and the difference in refractive indices between sphere and medium. In addition to using plastic spheres, another group developed two alternative “soft” cavities, one using dyed oil droplets and the other using the naturally occurring lipid droplets in some cells. Both of which, they show, can also create microlasers. Since each spherical cavity has a slightly different radius, producing laser light of a different wavelength for each cell, this technique can be used to observe cell behaviour on an individual level, in contrast to other cell-tracking methods. It may have profound effects for the in vivo imaging of the migration of cells in cancerous tumours and immune system responses.


References:
http://www.nature.com/nphoton/journal/v9/n9/full/nphoton.2015.129.html
http://pubs.acs.org/doi/abs/10.1021%2Facs.nanolett.5b02491