CRISPR and Cas9 are words that excited many, but the idea can also be confusing. DNA, RNA, what does that mean? We got you covered.
CRISPR is the name given to a DNA-editing tool. Its actually naturally occuring in bacteria, used to protect themselves against any viruses. When viral DNA from a virus enters the bacteria and is detected, it releases two short RNA sequences.
The two RNA strips form a complex with a nuclease. Thats called Cas9. Its easiest to think of the whole thing as cut and paste: the Nucleases are the scissors that do the DNA cutting.
One of the RNA strips has a sequence that is ‘complementary’ to the virus. That’s called a ‘Guide Sequence’. This sequence binds with the viral genetic code, bringing it together with the Cas9. If Cas9 is the scissors, the guide sequence RNA are the dashed lines saying “cut here”
Once the Cas9 enzyme and guide sequence enter the viral cells, the enzyme can cut the targeted area of genes.