The CRISPR/Cas9 system has been causing ripples in the scientific community ever since its mechanisms were reported in 2012. Commonly referred to as a genome editing tool, many scientists have found different applications for the scissor-like properties of the Cas9-protein. Researchers from the Leibniz Institute of Plant Genetics and Crop Plant Research (IPK Gatersleben) have now found a way to utilise the RNA/protein complex in a slightly different way—as a cytogenetic torch. Other than in conventional in situ hybridisation, the new RNA-guided endonuclease—in situ labelling-tool (RGEN-ISL) no longer requires denaturation of the DNA. The new method therefore leaves the chromatin intact, enabling investigation of the structure of the sample. Moreover, RGEN-ISL can be combined with protein-detection methods and allows real-time visualisation of the labelling-process. Whilst initially developed for plant genomes, RGEN-ISL can be used in all organisms and shows to be a promising new tool in the field of chromosome biology.