How to Avoid False-Negative and False-Positive COVID-19 PCR Testing

Abstract

Background: Up to 40% of test results for COVID-19 in the presence of clinical manifestations of the disease might be negative. The reason for a false-negative result might originate from any step of the analysis: poor-quality or empty swab, poor RNA isolation, inactivation of reverse transcriptase or Taq polymerase in the test. Methods: Here we describe a PCR approach for SARS-CoV-2 detection with swab quality and integrity controlled by human ABL1 mRNA amplification. Designed primers work with the cDNA of the ABL1 gene, not genomic DNA. Results: The simultaneous appearance of three signals corresponding to the nucleocapsid, spike, and ABL1 gene indicates infection with the Omicron strain. The amplification of ABL1 gene and nucleocapsid only indicate other than Omicron infection. The appearance of ABL1 amplification only indicates a true negative result for SARS-CoV-2. All other variants are null and void. Conclusions: A system has been developed for multiplex PCR diagnostics of SARS-CoV-2, which makes it possible to eliminate errors leading to false-negative and false-positive results at all stages of analysis. This is accomplished by the presence of specific primers for human RNA, controlling proper swab application, handling, and all the stages of RT-PCR.