Comparison between CLIA & ELISA Inclination towards High throughput Advanced Technique over Conventional Method of Diagnosis Rajeev Kumar, N. Nanda Gopal, Richa Baranwal, Rajesh Sharma, Reba Chhabra, Surinder Singh National Institute of Biologicals (NIB) Ministry of Health & Family Welfare, Government of India, NOIDA Abstract Immunoassays are valuable tools for the detection of blood borne diseases and per se are widely used for detection of specific antigen and / or antibodies present in the sample of interest in all over world. In the past three decades so many new principle based immunoassays for screening of blood borne diseases like Hepatitis B Virus (HBV), Hepatitis C Virus (HCV) and Human Immunodeficiency Virus (HIV) comes in the Indian market viz Rapid, Enzyme Linked Immunosorbent Assay (ELISA), Enzyme Linked Fluorescent Assay (ELFA) and Chemiluminescence Immuno Assay (CLIA). Hence, quality of these kits needs to be tested before release in the market for safe guarding of our population. Schematic Representation A. ELISA, B. CLIA Comparison between CLIA & ELISA CLIA ELISA High sensitivity Measure Relative light unit(RLU) Detection range is high Short duration Expensive No stop solution Comparatively low sensitivity Measure optical density(OD value) Detection range is low Long duration Low-priced Use stop solution Methodology Conventional Technique High throughput technique ELISA CLIA CLIA-Chemiluminescence Light Immunoassay Chemiluminescence is the production of light from a chemical reaction. Two chemicals react to form an excited (high-energy) intermediate, When the excited intermediates return back to their stable ground state, a photon is released, which is detected by the luminescent signal instrument. A + B -> AB* -> Products + Light Luminescent reactions are measured in Relative Light Units (RLU) that are proportionate to the amount of analyte present in a sample     Inclination towards CLIA technology Conclusion Benefits of CLIA CLIA is a better alternative method over conventional or traditional assays particularly ELISA for detection of antigen and / or antibodies of blood borne viruses. It can help in detecting early infection compared to ELISA and is suitable in large sample volume laboratories. Ultra-sensitive and can detect small amounts of the biological analyte. CLIA has advantages of being more reliable, precise technically simple and short incubation time. CLIAs have improved specificity and better positive predictive value. For Any other Information/Suggestions/Query, Kindly Contact: Dr. Reba Chhabra, Deputy Director (Quality Control) i/c Diagnostics E-mail: rchhabra@nib.gov.in