Chemiluminescent assays are currently the most popular assay due to their high sensitivity. These assays use antibodies conjugated to enzymes, such as peroxidase or alkaline phosphatase. When mixed with chemiluminescent substrates, these enzymes produce light in the visible spectrum.
A direct relationship exists between the amount of drug present in the sample and the light units produced. This is measured by a luminometer in the instrument. Assays using chemiluminescence are more sensitive than immunoassays that generate a colored product.
