Advantages of CRISPR-Cas9

Less time consuming:


Unlike homologous recombination, which is a time-consuming process, CRISPR-Cas9 is a less time taking process. There are two guide RNAs (ribonucleic acid) that guide the gene Cas9 to their location in the genome. The Cas9 gene already knows where it must go.


Better than homologous recombination:


On the other hand, in homologous recombination, the DNA (deoxyribonucleic acid) strand that is being inserted does not know where it must go. It first scans the genome for its homologous regions; this scanning part takes most of the time.




Note that in homologous recombination, once the gene of interest is inserted, it may cause other mutations like deletions, inversions, insertions etc. This does not occur with CRISPR-Cas9 system, because the nuclease Cas9 gene cuts at a very specific position of the double stranded DNA.




The CRISPR-Cas9 system is much simple than other gene editing tools. As mentioned above, there is a gene named as Cas9, and two guide RNA molecules.  One of the guide RNA is designed in such a way, that it will take the Cas9 gene to the exact place in the genome where repair is required. The second guide RNA enables the linking between the first guide RNA and Cas9 possible.




Cutting of defective exon 23 of the dystrophin gene has been made possible via this technique in mice. So, the utility and efficiency of this technique is unquestionable.