Chemiluminescence immunoassay (CLIA) is a laboratory technique that uses chemiluminescence to detect the presence and quantity of analytes like proteins, peptides, hormones, drugs and biomarkers. In CLIA, an antibody is attached to a chemiluminescent compound that will emit light upon reaction. This light emission can then be quantified to determine the concentration of the analyte in a biological sample.
How does Chemiluminescence Immuno Work?
In CLIA, the analyte in a sample binds to an antibody that is attached to a Chemiluminescence Immunoassay molecule. The antibody-antigen complex is then exposed to a catalyst that triggers the chemiluminescent molecule to emit light. The amount of light produced is directly proportional to the concentration of the analyte present in the sample. Modern CLIA systems use monoclonal antibodies tagged with acridinium esters as the standard chemiluminescent conjugate. Upon exposure to hydrogen peroxide and an alkaline solution, acridinium esters undergo an oxidizing reaction that produces a flash of light. This light emission can then be measured using a luminometer and converted into quantitative results.
Advantages of CLIA Over Other Detection Techniques
Compared to other immunoassay techniques like enzyme-linked immunosorbent assay (ELISA), CLIA offers several advantages:
– Sensitivity: CLIA is 10-100 times more sensitive than ELISA thanks to its ability to detect even single photon emissions. This allows it to detect analytes at much lower concentrations.
– Speed: The chemiluminescence reaction is faster than enzymatic reactions used in ELISA. CLIA tests can be completed within an hour compared to several hours for ELISA.
– Simplicity: CLIA assays involve fewer steps than sandwich ELISA and are simpler to perform. There is no need for enzymatic substrate addition or incubation.
– Stability: The chemiluminescent conjugates used in CLIA are extremely stable and do not require cold storage like enzymes. This makes CLIA more suitable for point-of-care testing.
Applications of CLIA in Clinical Laboratories
Due to its high sensitivity and speed, CLIA has become the immunoassay of choice for various clinical diagnostic applications:
– Therapeutic Drug Monitoring: CLIA is commonly used to detect drug levels for drugs like digoxin, phenytoin and theophylline in patients undergoing drug therapy.
– Endocrinology: It is frequently used for hormone assays like thyroxine (T4), tri-iodothyronine (T3), cortisol and vitamin D.
– Infectious Disease Testing: CLIA systems can detect biomarkers of infectious agents to diagnose diseases like Hepatitis, HIV, Syphilis etc.
– Cardiac Marker Testing: CRP, Troponin I/T and myoglobin are routinely quantified by CLIA for cardiac risk assessment and injury diagnosis.
– Toxicology Screening: CLIA plays a vital role in workplace drug testing and forensic toxicology investigations.
Advancing CLIA Technology for Improved Performance
Researchers are continuously working to enhance CLIA systems by developing more stable chemiluminescent labels, efficient catalyst systems and automated high-throughput platforms:
– Novel labels like acridinium ester conjugates are being designed for maximum light output and shelf life.
– New alkaline peroxide-based solutions demonstrate prolonged stability as CLIA reagents.
– Fully-automated CLIA analyzers with random-access capabilities, faster reaction times and quality control are becoming common in large clinical labs.
– Multiplex CLIA using different colored chemiluminescent signals allows detection of several analytes in one assay.
– Microfluidics-based CLIA chips enable miniaturized, portable testing with low sample volumes.
Chemiluminescence immunoassay technology provides laboratories with a highly sensitive, quick and simple method of detecting various clinically important analytes. Its widespread usage in diagnostic testing speaks to the numerous advantages it offers over other immunoassays. Continued refinement of CLIA systems will help bring this powerful technique to an even wider range of biomedical and research applications.
*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it.
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Money Singh is a seasoned content writer with over four years of experience in the market research sector. Her expertise spans various industries, including food and beverages, biotechnology, chemical and materials, defense and aerospace, consumer goods, etc. (https://www.linkedin.com/in/money-singh-590844163)_