Chemiluminescence immunoassays, also known as chemiluminescent immunoassay or abbreviated CLIA, are clinical assay tests used in clinical diagnostics for the detection and determination of antigen-antibody complexes in a clinical sample; also capable of multiplexed detection of multi-analytes. Enzymes label the proteins, such as horeseradish peroxidase (HRP) or alkaline phosphatase (ALP). Overall, it is a highly sensitive technique with good specificity for low detection in a clinical sample.