CRISPR-CAS9 gene guide RNA. Illustration of the guide RNA sequence of the CRISPR-Cas9 gene editing complex from the Streptococcus pyogenes bacterium. The CRISPR-Cas9 protein is used in genome engineering to cut DNA (deoxyribonucleic acid). It uses this guide RNA (ribonucleic acid) sequence to cut DNA at a complementary site CRISPR (Clustered Regularly Interspersed Palindromic Repeats) is a bacterial adaptive immunity system. For the full gene editing complex, see image C029/1634.