It doesn’t. It removes the target gene and cuts it into small segments. If there is no replacement, the cell will repair the DNA, most likely getting the order wrong and ending up with useless code. If there is a replacement gene, the cell will insert the replacement at the break and maybe insert a few of the junk gene pieces.
TheSeaOfTime t1_iy0ksax wrote
Reply to How exactly does CRISPR-CAS9 insert new genes? by AutomaticAd1918
It doesn’t. It removes the target gene and cuts it into small segments. If there is no replacement, the cell will repair the DNA, most likely getting the order wrong and ending up with useless code. If there is a replacement gene, the cell will insert the replacement at the break and maybe insert a few of the junk gene pieces.