SARS-CoV-2 Variant B.1.1.7 Multiplex RT-qPCR Screening Kit

Coronaviruses are a family of large RNA viruses with size ranging from 26 to 32 kb. These viruses are zoonotic and in humans can cause respiratory infections. As the coronavirus is an RNA virus, it has a relatively high mutation rate resulting in rapid evolution. In December 2019, a new deadly coronavirus known as SARS-CoV-2, which has a high sequence similarity to SARS-CoV, was identified as the cause of the Covid-19 outbreak. Since then, numerous variants of SARS-CoV-2 were reported around the world. Among them, one variant strain first identified in the United Kingdom, known as the B.1.1.7 lineage, has gained enormous attention because it has a much higher infection rate and has become a major strain spreading globally. Among the total of 23 mutations accumulated in the B.1.1.7 lineage, two mutations are thought responsible for the increased transmissibility. The spike-HV 69-70 deletion mutation may promote viral immune escape, and the spike-N501Y mutation may contribute to the higher viral binding affinity to the ACE2 receptor on the human cell membrane. Between these two mutations, the spike-HV 69-70 deletion is considered the hallmark of the B.1.1.7 lineage, as it is not present in other major circulating SARS-CoV-2 strains including 501Y.V2, P.1, and P.2.

ScienCell's SARS-CoV-2 Variant B.1.1.7 Multiplex RT-qPCR Screening Kit (SCVUK) is designed to screen for the possible presence of the B.1.1.7 lineage by detecting the spike-HV 69-70 deletion. Two multiplex primer/probe set components (Cat #7118-REF and #7118-H69V70) are included in the kit. The reference primer/probe set component (Cat #7118-REF) contains 3 primer/probe sets, N1-FAM, N2-FAM, and RP-HEX (Table 1). Among them, N1-FAM and N2-FAM target two regions on the coronavirus SARS-CoV-2 nucleocapsid (N) gene. RP-HEX targets the exon 1 of human RPP30 gene and serves as a control to assess specimen quality. The HV 69-70 primer/probe set component (Cat #7118-H69V70) contains 2 primer/probe sets, H69V70-Del-FAM and H69V70-Present-HEX (Table 2), which target the coronavirus SARS-CoV-2 spike (S) gene with HV 69-70 deleted and present, respectively. For more efficient screening, if the expected mutation rate is low, a pool of up to 10 RNA samples can be used as the template for one qPCR reaction. If results for H69V70-Del-FAM are negative, then all pooled samples do not contain the spike-HV 69-70 deletion mutation. For H69V70-Del-FAM positive pooled samples, the samples should be tested individually to identify the H69V70-Del-FAM positive one(s). Please refer to Tables 6 and 7 for results interpretation.