Guide RNA (gRNA) a particular RNA sequence that identifies the target DNA's area of interest. It attaches itself to the Cas9 protein and guides it to the intended location to transmit the change. In laboratories, recombinant gRNA is used in conjunction with other reagents to carry out a variety of assays such as multiplex PCR, classic PCR, complete genome sequencing cloning procedures cell line growth, primers, and recombinant plasmid DNA, in addition to mismatch assays for mutations, DNA modification, and gene expression research