Used for detecting and quantifying specific proteins, antibodies, or antigens in biological samples such as serum, plasma, or cell lysates. Commonly applied in medical diagnostics to identify infectious diseases like HIV, hepatitis, and Lyme disease. Also used in research settings to measure cytokine levels, hormone concentrations, and immune responses. Widely utilized in pharmaceutical development for monitoring biomarkers during drug trials. Offers high sensitivity and specificity, making it a reliable method in both clinical and laboratory environments.