Genome Sequencing and COVID-19

COVID-19, a disease caused by the coronavirus, SARS-CoV-2, will forever be linked to one of the most devastating outbreaks the world has ever known. As the virus is highly infectious, it has rapidly spread across the globe, and as a result, the World Health Organization (WHO) on March 11, 2020 declared the COVID-19 outbreak as a pandemic. As of April 30, 2020, over 3.23 million people are infected, and over 230 thousand people have died as a result. Understanding the genetic constitution of the virus is vital to the identification and development of treatment and control strategies against the disease.

A group of scientists in Korea has reported that they have sequenced the complete genome of the SARS-Cov-2 virus. For the study, they collected Nasopharyngeal and oropharyngeal swab and sputum samples from the infected individuals. RNA was extracted from the samples and used for the real-time reverse transcriptase (RT) PCR to confirm the occurrence of the virus in the patients. Following confirmation, the research team isolated the virus from positively infected cells and were cultured on to Vero cells. RNA from the cultured cells was isolated and synthesized to cDNA. SARS-CoV-2 specific primers were used to amplify the viral cDNA, and the amplified cDNA was used to prepare NGS libraries for sequencing using the Illumina MiSeq.  From the sequences, a complete genome of the virus was assembled using Megahit. The assembly revealed that the genome size of the virus was 28,818bp. When the genome sequence of the virus was blasted against the sequence database of animal and human SARS-like viruses, it resulted in 99.94%–99.99% similarity with other isolated SARS-Cov-2 virus sequences.