Citation: Chekani-Azar S, Gharib Mombeni E, Birhan M, and Yousefi M. CRISPR/Cas9 gene editing technology and its application to the coronavirus disease (COVID-19), a review. J Life Sci Biomed, 2020; 10(1): 01-09; DOI: https://dx.doi.org/10.36380/scil.2020.jlsb1 1 2020 SCIENCELINE Journal of Life Science and Biomedicine J Life Sci Biomed, 10 (1): 01-09, 2020 License: CC BY 4.0 ISSN 2251-9939 CRISPR/Cas9 gene editing technology and its application to the coronavirus disease (COVID-19), a review Saeid CHEKANI-AZAR, Ehsan GHARIB MOMBENI 3 , Mastewal BIRHAN 1* , and Mahshad YOUSEFI 2 1 PhD, Faculty of Veterinary Medicine, Animal Physiology, Atatürk University, Turkey 2 Department of Pathobiology, Shahid Chamran University of Ahvaz, Iran 3 College of Veterinary Medicine and Animal Science, Department Veterinary Paraclinical Studies, University of Gondar, Ethiopia 4 MD, Hamadan University of Medical Sciences, Hamadan, Iran Corresponding author’s Email: maste675@gmail.com; : 0000-0002-0984-5582 ABSTRACT Introduction. Clustered-Regularly Interspaced Short Palindromic Repeats (CRISPR), and CRISPR associated (Cas) protein (CRISPR/Cas) structures were first identified in E. coli in 1987 and guard prokaryotic cells from any invading pathogens, harmful events and plasmids by recognizing and cutting foreign nucleic acid sequences that contain short palindromic repeats spacer sequences. Several genome editing approaches have been developed based on these mechanisms; the most recent is known as CRISPR/Cas. Before the CRISPR technique was revealed in 2012, editing the genomes of plants and animals took many years and cost hundreds of thousands of dollars. Thus, CRISPR/Cas has attracted significant interest in the scientific community, especially for disease diagnosis and treatment, as it is quicker, less expensive and more precise than other genome editing approaches. The evidence from gene mutations in specific patients generated using CRISPR/Cas can assist in the prediction of the optimal treatment schedule for individual patients and for innovation purposes in other researches like replication in cell culture of coronaviruses like severe acute respiratory syndrome coronavirus-2 (SARS-CoV2 or COVID-19). However, in numerous situations, the effects of the furthermost significant driver mutations are not yet understood and interpretation of the optimal treatment is impossible. CRISPR/Cas classifications feature highly sensitive and selective tools for the detection of various target genes. When we see the next steps of genomic research are genome-wide association studies are a relatively new way to identify the genes involved in human disease. Furthermore, CRISPR/Cas provides a tool to manipulate non-coding regions and will thus accelerate examination of these poorly characterized regions of the genome and play a vital role in the progress of whole genome libraries. Aim. We aimed to review the history of CRISPR/Cas, the mechanisms of CRISPR techniques, and explore how CRISPR/Cas may improve the treatment of diseases and also review the current status of CRISPR/Cas as a tool for studying both natural mutations and genomic manipulations. Review Article PII: S225199392000001-10 Rec. 22 December 2019 Rev. 15 January 2020 Pub. 25 January 2020 Keywords CRISPR/Cas9, DNA-targeting, Palindromic, Plasmids, Genome sequencing, SARS-CoV2, COVID-19 INTRODUCTION Clustered regularly interspersed short palindromic repeats (CRISPR) were first discovered in Escherichia coli in 1987 and later found in other bacteria species. The role of these repeat sequences remained unclear until, in 2005, several researchers described the similarities of the sequences` DNA, leading to the hypothesis that the sequences are part of adaptive immune system in bacteria (CRISPR/Cas9 for cancer research and therapy). As you know, CRISPR is also refers to an adaptive immune response in bacteria and archaea that is cast-off to target and cut down viral DNA by using endonuclease in specific ways. By reengineering this immune response to target parts of genetic material, scientists could make extremely precise genetic alterations tailored to the type of cell. This is the basis of CRISPR therapeutic and diagnostic platforms [1]. CRISPR and CRISPR-associated proteins characterize the immune system of archaea and bacteria, and deliver protection against invasive nucleic acids, DNA, or RNA from phages, plasmids, and other exogenous DNA elements. At this time, two different classes, six types, and 21 subtypes of CRISPR–Cas systems have been identified [2]. The length of the repeat sequences varies between 25 and 40 nt, whereas the length of the spacer sequences varies between 21 and 71 nt [3]. DOI: https://dx.doi.org/10.36380/scil.2020.jlsb1