Quantitative colorimetric assay. This assay has high sensitivity and excellent specificity for detection of human PS2. No significant cross-reactivity or interference between human PS2 and analogues was observed. Note: Limited by current skills and knowledge, it is impossible for us to complete the cross-reactivity detection between human PS2 and all the analogues, therefore, cross reaction may still exist. Sample types: plasma, serum, tissue homogenates. Range: 2 - 80 ng/ml. Precision: Intra-Assay: CV<15% / Inter-Assay: CV<15%. Time: 2.5 hours