ELISA kits are widely used in medical and research laboratories for detecting and quantifying substances such as peptides, proteins, antibodies, and hormones. They are essential in diagnosing infectious diseases like HIV, hepatitis, and Lyme disease by identifying specific antigens or antibodies in blood samples. In clinical settings, ELISA kits support allergy testing, autoimmune disease detection, and monitoring disease progression. In research, they help analyze cytokines, growth factors, and signaling molecules in cell culture and tissue samples. Their high sensitivity, specificity, and ability to process multiple samples at once make them a standard tool in immunoassays. ELISA kits are also used in food safety testing to detect allergens or contaminants and in pharmaceutical development for quality control and biomarker analysis.