Crispr-based Genome Editing

In just a few years since its discovery Crispr-based gene editing technology revolutionized molecular biology and became not only one of the most powerful tools for genomic manipulation in the lab but also one of the biggest hopes in advancing gene therapy. Clustered Regularly Interspaced Short Palindromic Repeats or simply CRISPR technology is based on a form adaptive immunity in bacteria which utilizes short DNA sequences to “remember” and later disable bacteriophages (viruses which attack bacteria). This system has been been modified for genome engineering in the lab. CRISPR has rapidly become the most popular genome engineering approach due to its comparative simplicity and adaptability,
Two main components, a guide RNA (gRNA or sgRNA) and a CRISPR-associated endonuclease called Cas protein are present in the engineered CRISPR system. The short synthetic guide RNA composed of a scaffold sequence which is necessary for Cas protein binding and a ∼20 nucleotide spacer that defines the genomic target to be modified. Thus, genomic targets of the Cas protein can be changed by simply changing the target sequence present in the gRNA.
Knock out target genes in various cell types and organisms was originally employed by CRISPR. Advantages related to modifications of various Cas enzymes have extended CRISPR to selectively activate/repress target genes, image DNA in live cells, purify specific regions of DNA and precisely edit DNA and RNA. Moreover, ease of generating gRNAs makes CRISPR one of the most scalable genome editing technologies. This advancement also makes CRISPR perfect for genome-wide screens.