Three fast-spreading new variants of SARS-CoV-2 virus have emerged in recent months: the U.K. variant B.1.1.7, the Brazil variant P.1, and the South Africa variant B.1.351.
A subset of the mutations identified in the RBD domain of the spike protein occurs in more than one strain, although the three variants are believed to be independently evolved. These convergent mutations, specifically, the N501Y (shared by all three, 40592-V08H82) and E484K (shared between B.1.351 and P.1, 40592-V08H84), are of high interest because they may be the cause of the increased transmissibility.
The mutations in these strains also occur in the nucleocapsid protein, which is commonly used as the biomarker in rapid antigen tests. It’s critical to assess whether the current commercial antigen tests can detect the mutated N proteins with the same sensitivity and specificity as their WT counterpart.
Sino Biological has developed a panel of recombinant RBD/Spike and nucleocapsid protein variants carrying the aforementioned mutations as below:
Sino Biological has developed a large panel of antibodies against SARS-CoV-2 N protein and the S protein. Extensive testing was performed and we have identified several pairs for each of the two targets. These pairs can be used to assemble detection assays for the corresponding antigen.