GENLISA™ SARS-CoV-2 (Covid-19) Neutralizing Antibody ELISA

ELISA for the quantitative determination of neutralizing antibodies to COVID-19 in human serum and plasma samples. Also known as the sVNT assay. CE IVD marked

Introduction:
The GENLISA™ ELISA kits are used for assessing the specific biomarker in samples analytes which may be
serum, plasma and cell culture supernatant as validated with the kit. The kit employs a blocking ELISA
technique which mimics the virus neutralization process.
SARS-CoV-2-neutralizing antibodies primarily target the trimeric spike (S) glycoproteins on the viral surface
that mediate entry into host cells. The S protein has two functional subunits that mediate cell attachment (the
S1 subunit, existing of four core domains S1A through S1D) and fusion of the viral and cellular membrane (the
S2 subunit).
Potent neutralizing antibodies often target the receptor interaction site in S1, disabling receptor interactions.
The spike proteins of SARS-CoV-2 commonly bind to the human angiotensin coverting enzyme 2 (ACE2)
protein as a host receptor through their S1B domain. Receptor interaction is known to trigger irreversible
conformational changes in coronavirus spike proteins enabling membrane fusion.
SARS-CoV-2 initiates an immune response, which leads to the production of antibodies. These neutralizing
antibodies provide protection against future infection from SARS-CoV-2, as they remain in the circulatory
system for months to years post infection.

Intended Use:
The GENLISA™ SARS-CoV-2 (Covid-19) Surrogate Virus Neutralization Test (sVNT) ELISA kit is used as an
analytical tool for the qualitative and quantitative detection all types of neutralizing antibodies against SARSCoV-2 in serum or plasma.

Principle:
The method employs sandwich ELISA technique. The protein-protein interaction between HRP-RBD and
hACE2 can be blocked by neutralizing antibodies against SARS-CoV-2 RBD.
Samples and controls are pipetted in a blank microtitre plate and incubated with HRP conjugated human SARSCoV-2 RBD protein. The antibodies to SARS-CoV-2 present in the samples and controls bind to the SARSCoV-2 RBD protein to form a complex.
This solution of bound and unbound antibodies to SARS-CoV-2 is then pipetted into human ACE2 coated
microplate. After washing to remove the bound complex of Anti-SARS-CoV-2 and HRP conjugated SARSCoV-2 RBD, the substrate solution (TMB) is added to the microwells. Post incubation, color develops
proportionally to the amount of unbound Anti-SARS-CoV-2 (Covid-19) present in the sample. Color
development is then stopped by addition of stop solution. Absorbance is measured at 450 nm.