kjemiluminescensimmunoassay

Kjemiluminescensimmunoassay, also known as chemiluminescence immunoassay (CLIA), is a widely used type of immunoassay that employs chemiluminescent labels to detect and quantify analytes in biological samples. In a CLIA, an antigen–antibody interaction is coupled to a chemical reaction that produces light. The resulting luminescence is measured with a luminometer, and the signal strength is proportional to the amount of target analyte present.

CLIA assays can be organized into two main formats: sandwich assays for larger molecules and competitive assays for small molecules. In a sandwich CLIA, a capture antibody binds the analyte, and a second, labeled antibody provides the light-emitting signal. In a competitive CLIA, a labeled analyte competes with the sample antigen for binding sites, and the signal inversely reflects the concentration. Many CLIA platforms are automated and use solid supports or magnetic particles to streamline washing and separation.

Applications and performance: CLIA is widely used in clinical diagnostics to measure hormones, proteins, infectious disease markers, cardiac biomarkers such as troponin, tumor markers, and therapeutic drugs. Advantages include high sensitivity, broad dynamic range, rapid turnaround, and suitability for high-throughput testing and multiplexing. Limitations can include cross-reactivity or interference from heterophile antibodies, matrix effects, and, in some sandwich assays, the hook effect at very high analyte levels. Robust quality control and proper calibration are essential for reliable results.