DNA Sequencing Explains How Scientists Identify COVID-19 Variants
Scientists use DNA sequencing to track mutations in the SARS-CoV-2 virus and identify new variants like Omicron. This process reveals changes in the virus's genetic code that affect how it spreads and evades immunity.
Scientists identify new COVID-19 variants through a process called DNA sequencing, which determines the exact order of the four chemical building blocks that make up the virus's genetic material. When the SARS-CoV-2 virus replicates, copying errors introduce mutations that swap, delete, or insert these genetic building blocks. These mutations alter the virus's genes and can change its physical characteristics, including its ability to spread, cause infection, or evade the human immune system.
Researchers use various sequencing technologies to read these viral genomes, starting with older methods like Sanger sequencing developed in the 1970s. Sanger sequencing cuts DNA into short fragments and uses fluorescent tags to identify each nucleotide, providing highly accurate data despite being relatively slow. Some scientists continue to use this reliable method today to process SARS-CoV-2 samples and confirm specific mutations.
Since the late 1990s, next-generation sequencing (NGS) revolutionizes this field by processing much higher volumes of DNA simultaneously and significantly reducing the time required to sequence a genome. These faster NGS platforms allow researchers to rapidly track emerging variants like Omicron. The same genomic tools that microbiologists use to study bacterial antibiotic resistance are now essential for global efforts to monitor and respond to the evolving coronavirus.