Access sars cov 2 igg 2

Serological tests were performed using a two-step enzyme IgG chemiluminescent immunoassay—Access SARS-CoV-2 IgG II (Beckman Coulter Inc., Brea, CA, USA). This method is based on the patient’s serum reaction with a recombinant SARS-CoV-2 spike 1 protein (S1) containing the sequence of the receptor-binding domain (RBD). The results were defined according to the manufacturer’s instructions as reactive for SARS-CoV-2 (seropositive) when the titer of IgG against RBD of the S1 protein was ≥10.00 AU/mL and as non-reactive (seronegative) when the value of antibodies was <10.00 AU/mL. Our pilot study described the research methodology in detail [16 (link)].

The commercial Access SARS-CoV-2 IgG II (Beckman Coulter) chemiluminescent immunoassay was used as a comparative test intended for the semi-quantitative determination of IgG antibodies to SARS-CoV-2 receptor binding domain (RBD). The amount of anti-SARS-CoV-2 RBD IgG antibodies in the sample is determined from a stored multipoint calibration curve. All tests were conducted according to the manufacturer's recommendations. A cut-off of 30 IU/mL was used for positivity as recommended by the manufacturer.

The Access SARS-CoV-2 IgG II (Beckman Coulter, Brea, CA, USA) assay is a paramagnetic particle, chemiluminescent immunoassay for the semi-quantitative and qualitative detection of anti-S-RBD IgG antibody. The measurement was performed by indirect chemiluminescence immunoassay on Access 2 (Beckman Coulter) instrumentation, according to the manufacturer’s instructions. The assay has a limit of detection (LoD) of ≤ 2.00 arbitrary unit (AU)/mL, as declared by the manufacturer.