This kit, designed for Human Cystatin-Sa (CST2) detection, features a pre-coated assay plate with mouse anti-Human Cystatin SA monoclonal antibody. Upon adding a sample containing Cystatin SA, it binds to the well-coated antibodies. Subsequently, a horseradish peroxidase conjugated mouse anti-Human Cystatin SA Antibody is added, binding to Cystatin SA in the sample. After washing, substrate solutions are added, with color intensity directly proportional to Human Cystatin SA present. The reaction is halted with an acidic stop solution, and absorbance is measured at 450 nm.