The catalytically dead Cas9 protein (dCas9) is well known for its ability to bind DNA targets without changing them. Thus, it has been widely adapted for CRISPR activation and inhibition experiments. But over the past few years, dCas9 has become a robust visualization tool to study the spatial and temporal arrangement of chromosomes and how these arrangements may affect nuclear processes. The latest of these visualization tools is CRISPR-Sirius, the brightest CRISPR-based tool to date for visualizing genomic loci in living cells.
