Relevant factors of the RT-PCR assay for the detection of SARS-CoV-2, etiologic agent of COVID-19

Abstract

Availability of the SARS-CoV-2 sequence since January 2020, allowed the implementation of reverse-transcriptase polymerase chain reaction assays in real-time to detect the virus. Diverse sample types, reagents, and conditions have been standardized in different countries to use the assay as a confirmative test of patients with COVID-19, following the indications established by WHO due to it high sensitivity and specificity.  General conditions to achieve reliable results from this test involve factors such as the acquisition of nucleic acids with acceptable quality and quantity, from suitable samples that unequivocally indicate the presence of the virus in patients even at the early stages of the infection.  This article describes diagnostic techniques and procedures used by different available protocols for the detection of SARS-CoV-2 through RT-PCR assays, comparing performance parameters, which allow to recognize strategies that can be used to improve this type of diagnostic tests.