Enzymes are biological catalysts that speed up chemical reactions without being consumed in the process. In ELISAs, enzymes such as horseradish peroxidase (HRP) or alkaline phosphatase are conjugated to antibodies or antigens. When the target analyte binds to a specific antibody, the enzyme catalyzes a reaction that produces a measurable signal, typically a color change or fluorescence, enabling the detection and quantification of the analyte.
