Sandwich Assay Manufacturing Services

The sandwich-based immunoassay provides greater assay sensitivity and semi-quantitative capability, but requires a larger analyte with multiple antibody binding sites, such as LH, hCG, H. pylori, PSA, TNI and HIV. The target molecule is first bound by a nanogold-conjugated primary monoclonal antibody which is then captured by a secondary antibody embedded in the membrane to form a visible test, or T-line. All excess, unbound primary antibody flows past the T-line to be captured by a third antibody specific to the primary antibody, thus forming a visible control, or C-line. In the sandwich assay, a visible T-line represents a positive result for the analyte in question.