The digene HC2 GC-ID DNA Test is a nucleic acid hybridization assay with signal amplification that utilizes microplate chemiluminescent detection.
Specimens that contain the target DNA are hybridized with a specific GC RNA probe cocktail. The resultant RNA–DNA hybrids are captured onto the surface of a microplate well that is coated with antibodies specific for RNA–DNA hybrids. The immobilized hybrids are then reacted with alkaline phosphatase-conjugated antibodies that are specific for RNA–DNA hybrids, and are detected with a chemiluminescent substrate. Several alkaline phosphatase molecules are conjugated to each antibody. Multiple conjugated antibodies bind to each captured hybrid, resulting in substantial signal amplification. As the substrate is cleaved by the bound alkaline phosphatase, light is emitted, which is measured as relative light units (RLUs) on a luminometer. The intensity of the light emitted denotes the presence or absence of target DNA in the specimen.