Quantitative colorimetric assay. This assay has high sensitivity and excellent specificity for detection of human 17-alpha-OH. No significant cross-reactivity or interference between human 17-alpha-OH and analogues was observed. Note: Limited by current skills and knowledge, it is impossible for us to complete the cross-reactivity detection between human 17-alpha-OH and all the analogues, therefore, cross reaction may still exist. Sample types: plasma, serum, tissue homogenates. Range: 50 - 2000 pg/ml. Precision: Intra-Assay: CV<15% / Inter-Assay: CV<15%. Time: 2.5 hours