Chemiluminescence immunoassay (CLIA) is an antigen-antibody binding assay technique that utilizes the chemical reaction between luminol and an oxidizing agent like hydrogen peroxide or alkaline peroxide to generate light. This light production or chemiluminescence is then used to quantify the amount of antigen or antibody in a given sample. By combining the highly specific antigen-antibody reactions of immunoassays with the extreme sensitivity of chemiluminescence detection, CLIA provides researchers and clinicians an invaluable tool for biomarker measurement, disease diagnosis, and therapeutic drug monitoring.
Principle of Chemiluminescence Immuno
In a CLIA, the antigen or antibody of interest is labeled with an enzyme like horseradish peroxidase or alkaline phosphatase. During the antigen-antibody reaction, the conjugate is bound to either the solid phase or capture antibody. Unbound conjugate is then washed away. Next, the Chemiluminescence Immunoassay substrate such as luminol is added to the reaction. In the presence of the enzyme label and an oxidizing agent, luminol undergoes oxidation and produces light in the blue and green region of the visible spectrum. The intensity of this emitted light, which is directly proportional to the amount of antigen or antibody present, is measured with a luminometer. This signal provides a quantitative measurement of the analyte being detected.
Applications of CLIA in Biomedical Research
CLIA has numerous applications in biomedical research due to its high sensitivity and wide dynamic range. It is commonly used for the quantification of hormones, tumor markers, therapeutic drugs and cytokines involved in various disease processes. Some key areas where CLIA has made significant research contributions include:
– Cancer biomarker evaluation – CLIA is often the assay of choice for measuring circulating proteins like prostate specific antigen, CA125, and cortisol that can aid in cancer detection, staging and monitoring response to treatment.
– Cardiovascular disease research – CLIAs precisely measure blood levels of proteins linked to atherosclerosis, heart attack and stroke risk such as troponin, CRP and MMP9.
– Immunology and inflammation studies – The concentrations of cytokines, chemokines and other inflammatory mediators associated with diseases can be accurately determined using multiplex CLIA panels.
– Neurological disorder investigation – CLIAs support research on conditions like Alzheimer’s, Parkinson’s and multiple sclerosis by quantifying biomarkers in cerebrospinal fluid and blood.
– Infectious disease diagnostics – CLIAs play an important role in detecting viral, bacterial and parasitic pathogens through measurement of specific antibodies or antigens.
Clinical Applications of CLIA Diagnostic Testing
In addition to research applications, CLIA has emerged as a mainstay technology for clinical diagnostic testing due to its automation compatibility, wide dynamic range, and ability to analyze multiple analytes simultaneously in small sample volumes. Some key areas where CLIA is extensively utilized for diagnosis and monitoring of disease include:
– Routine chemistry testing – CLIA systems perform rapid, accurate analysis of electrolytes, cardiac markers, liver/kidney function tests and metabolic panel constituents.
– Thyroid function assessment – Tests for TSH, T3, T4 and thyroid antibodies rely on CLIA to evaluate thyroid disorders.
– Infectious disease screening – CLIAs detect antibodies for diseases such as HIV, hepatitis, lyme and syphilis.
– Therapeutic drug monitoring – levels of immunosuppressants, anticoagulants, antiepileptics and others can be quantified using CLIA.
– Tumor monitoring – CLIAs aid oncology patient management by quantifying tumor markers like CEA, AFP, PSA during and after treatment.
– Cardiac risk assessment – CLIAs are instrumental in evaluating cholesterol profiles, CRP and other cardiac risk factors.
– Toxicology testing – CLIAs support poison control and addiction treatment through drug screening of urine, blood or saliva.
Advantages of Chemiluminescence Immunoassay
Some key advantages of CLIA over other immunoassay platforms that explain its popularity include:
– Extremely high sensitivity – CLIA can detect analytes in the picogram/ml to femtogram/ml range, 1-3 logs more sensitive than ELISA.
– Wide dynamic range – Ability to accurately measure analyte levels over 5-6 logs of concentration compared to 2-3 logs for other methods.
– Minimal light interference – Chemiluminescent signal eliminates need for external light source and is unaffected by sample color/turbidity like other optical techniques.
– Rapid automated processing – CLIA analyzers can perform up to 200 tests per hour with random access capabilities and walk-away automation.
– Multi-analyte measurement – The technique lends itself readily to development of multiplex assays to simultaneously detect 6-10 analytes in a single reaction well.
Thanks to its high sensitivity, specificity, speed, automation suitability and multi-analyte analysis potential, CLIA has emerged as a powerful all-round technique with broad applications in biomedical research and clinical diagnostic testing. Continued technological innovations will likely see CLIA becoming even more useful and widespread going forward.
*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it.
About Author - Vaagisha Singh
Vaagisha brings over three years of expertise as a content editor in the market research domain. Originally a creative writer, she discovered her passion for editing, combining her flair for writing with a meticulous eye for detail. Her ability to craft and refine compelling content makes her an invaluable asset in delivering polished and engaging write-ups. LinkedIn