Cas9 Enzyme

Cas9 is an enzyme used for DNA editing and is a key component of the genetic editing tool known as CRISPR-Cas9 (Cas9 stands for CRISPR-associated protein 9). This mechanism is naturally used by bacteria, which cut the DNA of attacking viruses as a means of defense. Researchers have harnessed this mechanism to remove problematic segments from DNA, such as mutations. A guide RNA is used to identify the specific DNA segment to be removed and the Cas9 enzyme performs the cut.

However, CRISPR has several disadvantages; the main one being that its bacterial origin often causes the immune system to reject CRISPR as a foreign protein. Another significant issue is its relatively high rate of off-target activity, meaning unintended edits may occur in genome regions that share significant similarity with the intended sequence. This can leave mutations in the DNA, increasing the risk of cancer.