Antibodies
A 5cc whole blood sample was drawn (without anticoagulants), and serum
was derived from the specimen using centrifugation (3000xg for 10
minutes). The Enzyme-linked Immunosorbent Assay (ELISA) method (Pishtaz
Teb SARS-CoV-2 IgM and IgG- Iran) was used to test the serum antibody
levels. The test was performed according to the manufacturer’s
brochure. Results greater than 1.1 were considered positive and those
less than 0.9 as negative. Results within the mentioned range were
reported as borderline and the test was redone on a second, fresh serum
sample to confirm the initial results.
The manufacture reported diagnostic specifications of the test kits:
Specificity: 97.30% and Sensitivity: 79.40% for SARS-COV-2-IGM kit.
Specificity: 98.30%% and sensitivity: 91.10% for SARS-COV-2-IGG kit.