Abstract

REAL-TIME PCR OR QUANTITATIVE PCR (QPCR) – A REVOLUTION IN MODERN SCIENCE

Aswathy Jyothy*, Sowparnika Treasa Sabu and Shaiju S. Dharan

Abstract

Background: Polymerase chain reaction (PCR) is an efficient and powerful molecular tool to copy or amplify small segments of DNA or RNA. It has been modified and developed over the years to obtain a standardized tool in the biological science field. Real-time PCR is one of the most widely accepted gene amplification tools among all other types of PCR due to its tremendous range of advantages. It allows amplifying quantitatively as well as to detect the products during each cycle, through fluorescent dyes that yield increased fluorescent signal after each cycle. Quantitative PCR (qPCR) has a wide range of applications in the field of diagnosis, genetics, personalized therapy, forensic, environment. etc. Its uses begin from the quantification of HIV in the 1980s to the detection and diagnosis of SARS-Cov-2 virus causing the recent coronavirus disease (COVID-19) in 2020. Method: The review is done by referring research articles and review articles from various sites like Pubmed, google scholar, science direct, Canadian Journal of Infectious Diseases and Medical Microbiology, Journal of Clinical Microbiology and BioTechniques. Details regarding PCR were also obtained from Roche.com. WHO and US FDA sites were used to refer to details about COVID-19 and its diagnosis. The search was made using keywords like PCR, Real-Time PCR, COVID-19, quantitative, applications, steps and comparisons. Observations: PCR technique, since its evolution, has been developed or modified into various engineered models to provide accurate copies of desired DNA/RNA strands. Selection of any type of PCR is completely based on the experiment required and working conditions. Of these, Real-time PCR is considered the gold standard of most of the types as it allows quantitative detection and amplification of desired DNA/RNA during each cycle. This technique is currently widely accepted in many applications including the diagnosis of SARS-Cov-2, the virus causing the recent pandemic COVID-19. Though modified forms of PCR are widely accepted, it requires in-depth knowledge about the scientific aspects and chemistry in-order to assess proper conclusions.

Keywords: PCR, Real-time, quantitative, principles, applications, COVID-19, diagnostics.