How Does It Work? | CRISPR Mechanism

The CRISPR Cas9 System was first discovered as part of the bacterial adaptive immune response against viruses, but in recent years it’s revolutionized our techniques for genome editing.

The Cas9 complex is formed of two components. A protein called Cas9 that can cut double stranded DNA, and a guide RNA, that binds to a specific and predetermined DNA sequence.

Cas9 must first bind to a sequence of 2-6 DNA nucleotides known as a PAM.
If the DNA contains a sequence that is complimentary to the guide RNA, the double stranded DNA is unwound, forming complimentary pairs between the DNA and guide RNA.

Cas9 contains two cutting domains that can cleave both strands of DNA, causing a double-stranded break. The repair process can mutate or disable genes, allowing us to study their function in diseases.

However, the applications of CRISPR technology stretch far beyond knocking out genes. As new CRISPR technologies emerge in medicine, we’re likely to see a massive shift in ways that people can improve the lives of patients.