What is Cas9?

Cas9 is an RNA-guided DNA endonuclease enzyme associated with the CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) adaptive immune system in Streptococcus pyogenes. Cas9 unwinds DNA and cuts both strands, guided by an RNA sequence complementary to the target DNA. It is commonly used in gene editing to precisely modify DNA sequences within living organisms, enabling researchers to delete, insert, or replace specific genes.