What exactly does CRISPR do?

Finds target DNA – it uses a short RNA guide sequence to locate a matching DNA segment in the genome.

Cuts DNA – the Cas9 protein works like molecular scissors, making a break at the target location.

Triggers repair – the cell’s own repair machinery then fixes the break, either by joining the ends (causing small changes) or by inserting a new DNA piece provided by scientists.

Allows precise edits – by choosing the guide RNA and repair template, researchers can delete, replace, or add genes exactly where needed.