Used in biomedical research and clinical diagnostics to detect and quantify specific proteins, antibodies, or antigens in biological samples such as serum, plasma, or cell culture supernatants. Commonly applied in disease diagnosis including HIV, hepatitis, and COVID-19 antibody testing. Also used in food safety testing to identify allergens or contaminants, and in environmental monitoring to detect pollutants. Widely adopted due to high sensitivity, specificity, and ability to process multiple samples simultaneously.