Optical control of Cas9 activity through visible-light cleavable crRNAs

In this work, we present several visible-light cleavable crRNAs targeting two different genes for regulating Cas9 activity. The crRNAs contain a total of three different photocleavable linker (PL) which induce a bond break when irradiated with a suitable wavelength. Cleavage of the crRNAs efficiently inhibits Cas9 activity, as demonstrated by the in vitro Cas9 assay developed in this work. By using visible light, our approach will enable precise downregulation of Cas9 activity in terms of location and timing, thereby enabling non-invasive and harm free control over genome editing for safer application.