On-demand killing of adherent cells on photo-acid-generating culture substrates

As a powerful tool of cell screening and cell purification, we developed a novel method to kill adherent cells as cultured on a substrate by micro‐projection of incoherent visible light. To kill the cells by the mild light irradiated by electrically controllable micro‐projection systems currently available, we introduced the assist of the photo‐responsive culture substrates functionalized with a photo‐acid‐generating polymer. In clear contrast to the existing laser‐based methods requiring point scanning, areal micro‐prjection of blue light with the wavelength 436 nm killed many CHO‐K1 cells at a time in the irradiated area on the substrate. The effect of the photo‐generated acid was so confined that selective killing of targeted cells was achieved without critical damage to the neighboring cells. Further, we demonstrated the photo‐selective killing of the adherent cells after preliminarily patterning through the photo‐induced removal of cell adhesion‐inhibiting polymer. Biotechnol. Bioeng. 2013; 110: 348–352. © 2012 Wiley Periodicals, Inc. Novel method to kill adherent cells as cultured on a substrate by micro‐projection of mild visible light was developed by means of culture substrates functionalized with photo‐acid‐generating polymer. Patterned killing and in situ screening of CHO‐K1 cells were demonstrated by using a PC‐controlled micro‐pattern projection system. Further, photo‐selective killing after photo‐induced patterning of CHO‐K1 cells was achieved on a substrate.