The SARS-CoV-2 virus has spread globally with over >95 million reported cases. Although, RT-qPCR has emerged as the gold-standard method for diagnosis, upscaling these tests to meet current demand is difficult. One means of reducing costs whilst simultaneously increasing throughput is to perform pooled testing. However, the main shortcoming of pooled testing lies in the loss of sensitivity associated with diluted samples, leading to false negative results. Here we report a new method as a means of preserving and/or improving the sensitivity of pooled patient oro-nasopharyngeal lysates.. Comparing a spectrum of 340 COVID-19 positive and negative patients pooled lysates with individual PCR demonstrated that the loss in RT-qPCR sensitivity of pooled samples could be overcome with concentrators. We demonstrated that concentration of COVID-19 patient lysates could be successfully implemented for surveillance screening using pooling with minimal changes to standard workflow. Given that pooling reduces use of laboratory resources by up to 90% and only adds 15 minutes to the existing protocol, the described method will be indispensable for future surveillance testing. Given its simplicity, with no need for additional sophisticated instrumentation, our concentration approach could be used successfully to identify SARS-CoV-2 and other DNA/RNA pathogens (old and novel).
Vasudevan lab identifies novel means of improving sensitivity and efficiency for PCR COVID testing
Department Vasudevan Group
9 April 2021
In collaboration with the infectious disease units at the John Radcliffe and Churchill Hospitals, the Vasudevan lab has identified a novel means of improving RT-qPCR sensitivity and efficiency for the detection of SARS-CoV-2 through the concentration of pooled patient lysates.