Description
For the quantitative determination of human anti-COVID-19 spike protein S1 receptor-binding domain ELISA (IgG class antibodies) in serum
Introduction: Since December 2019, outbreak of COVID-19 infection has become a major epidemic threat in China and brought back the attention of pathogenic coronavirus to the spotlight. Spike protein is an envelope-anchored protein that mediates the recognition and binding of COVID-19 to host cells. S1 can be further cleaved by the host protease into two subunits called S1 and S2, wherein the S1 polypeptide contain a receptor binding domain (RBD) crucial for the specific recognition and interaction with human receptor ACE2, which is the first and the most essential step for the virus infection. Human anti-COVID-19 spike protein S1 receptor-binding domain (S1RBD) IgG ELISA kit is a highly sensitive and specific ELISA kit developed by ImmunoDiagnostics for the precision detection and quantitative measurement of titres of anti-S1RBD IgG class antibodies in human serum.
Assay Principle: Recombinant spike protein S1 receptor-binding domain (S1RBD) of COVID-19 (Cat No. 41A221) coated onto the plate wells can specifically recognize anti-S1RBD antibodies in human sera. After a 1 hour incubation, anti-S1RBD antibodies are captured by immobilized S1RBD protein while the unbound components were discarded and washed away. Afterwards, HRP-conjugated anti-human IgG is added for another 1 hour incubation, wherein the anti-human IgG detects IgG class antibodies previously bound to S1RBD protein on the plate. After removal of nonspecific bindings, bound anti-human IgG is revealed by the addition of substrate solution containing 3,3?,5,5?-Tetramethylbenzidine (TMB), resulting in the formation of a blue color. Color reaction will be further stopped by 2M H2SO4, transforming the blue color to yellow signals. The absorbance of yellow reaction mixture is measured by plate reader at 450nm. The higher the reading is, the higher concentration of anti-S1RBD IgGs