The development of various tools to alter the targeted sequence of the genome of a living organism is necessary in the biomedical research. Recently, a new tool based on a bacterial CRISPR-associated protein-9 nuclease (Cas9) from Streptococcus pyogenes was developed. In this type of genome editing, the short RNA search string is used to guide a Cas9 protein which is an endonuclease, into a specific location within a complex genome. The modified RNA recognizes the DNA sequence, and the Cas9 enzyme cuts the DNA at the targeted location. Once the DNA is cut, researchers use the cell’s own DNA repair machinery to add or delete pieces of genetic material, or to make changes to the DNA by replacing an existing segment with a customized DNA sequence. CRISPR Cas9 genome editing is used as an innovative tool in prevention and treatment of human diseases and animal diseases. Presently most of the research on genome editing is done to understand diseases using cells and animal models. This type of genome editing is used to target a protein domain for transcriptional regulations, epigenetic modification and microscopic visualization of specific genome loci. CRISPR cas9 has an advantage of introducing point mutations in a particular target gene using single guide RNA (gRNA). This enables rapid genome-wide interrogation of gene function by generating large guide RNA (gRNA) libraries for genomic screening. This system differs from the other method due to its simplicity, high efficiency, user friendly and versatility of the system. Any DNA sequence can be targeted by altering the first 20 nucleotides of the guide RNA (gRNA) for novel genome editing applications.