In our latest work, just published in Nano Letters we have turned living cells into self-sustained tiny lasers. By ingesting a whispering gallery mode resonator – basically a micrometre-sized coloured plastic bead – our cells gain the capability to produce green laser light. The spectral composition of the laser light generated by each bead is different and can therefore be used as a barcode-type tag for the cells. Using this approach large numbers of different cells – in principle up to several hundred thousand – can be distinguished and tracked over prolonged periods of time. In the future, this may enable new insights into important processes in biomedicine, e.g. by tracking how cancer cells invade tissue or by following how immune cells migrate to sites of inflammation.
Picture credit Gather/Schubert