Binan, L. et al. Nat. Commun. 7, 11636 (2016).

Kuo, C.-T. et al. Nat. Commun. 7, 11468 (2016).

For cells with distinctive behaviors or morphologies to be singled out from a population, they need to be individually marked before downstream analyses are carried out. Two related methods have been developed to achieve single-cell selection. Binan et al. incubate cell cultures with a biotin-conjugated fluorophore that releases reactive oxygen species upon targeted illumination with a laser beam and results in biotin cross-linking to the cell. Kuo et al. label cells with photoswitchable semiconducting polymer dots (Pdots) via antibodies directed to cell surface markers. Individual cells can then be selected on the basis of Pdot fluorescence, switched on with a laser beam. Neither approach interferes with cell viability. They both result in stable labeling, which the research teams harnessed to sort the labeled cells and to analyze their transcriptional profile or their genome.