Used extensively as a chromogenic substrate in enzyme-linked immunosorbent assays (ELISA), it facilitates the detection of antibodies or antigens by producing a blue color upon oxidation, which can be measured spectrophotometrically. Its application is crucial in medical diagnostics for detecting diseases, including HIV and hepatitis. Additionally, it serves in forensic science for blood detection at crime scenes, where it reacts with hemoglobin to indicate the presence of blood. Its sensitivity and specificity make it a valuable tool in biochemical research and clinical laboratories.