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 mutation was detected within the Spike protein of SARS-CoV-2 and is known as the spike-E484K mutation. This variant causes the amino acid glutamic acid at position 484 (E484) mutate to a lysine (K484), and it may contribute to the immune evasion of SARS-CoV-2 and dampen current vaccine efficacy. This mutation is present in some major circulating SARS-CoV-2 strains including 501Y.V2, P.1 and P.2.

ScienCell's SARS-CoV-2 E484K Mutation Multiplex RT-qPCR Screening Kit (SCVEK) is designed to screen for the presence of the SARS-CoV-2 spike-E484K mutation. Two multiplex primer/probe set components (Cat #7138-REF and #7138-E484K) are included in the kit. The reference primer/probe set component (Cat #7138-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 E484K primer/probe set component (Cat #7138-E484K) contains 2 primer/probe sets, K484-FAM and E484-HEX (Table 2), which target the coronavirus SARS-CoV-2 spike (S) gene with a lysine (K) and a glutamic acid (E) at position 484, respectively. For more efficient screening, if the expected E484K 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 K484-FAM are negative, then all pooled samples do not contain the E484K mutation. For K484-FAM positive pooled samples, the pooled samples should be tested individually to identify the E484K mutated one(s). Please refer to Tables 6 and 7 for results interpretation.