Linkcare seroscreening tests, or lateral-flow immuno-chromatography colloidal gold tests, work similarly to a pregnancy test. The assay tray is impregnated with SARS-CoV-2 antigens. When a drop of blood is placed in the well and begins to flow along the strip, the antigens work like bait, attracting and linking to antibodies against the virus if these are present in the blood. A darker line may indicate a higher viral load.

Product technology
Source: Brianna Abbott, Amy Dockser Marcus. Race Is On to Create Rapid Covid-19 Tests for the Fall. Wall Street Journal May 26, 2020 8:00 am ET

SARS-CoV-2 presents different antigens. The sensitivity and specificity of each test depends on the antigens that are used. Linkcare’s Seroscreening kits use the following high quality antigens: SARS-CoV-2 Spike protein (GenBank: MN908947), Spike S-RBD-SD1 domain QHD43416.1 and SARS-Cov-2 Nucleocapsid protein (Genbank: MN908947.3 Nucleocapsid protein QHD43423.2)