Quantitative colorimetric assay. This assay has high sensitivity and excellent specificity for detection of rat AFU. No significant cross-reactivity or interference between rat AFU and analogues was observed. Note: Limited by current skills and knowledge, it is impossible for us to complete the cross-reactivity detection between rat AFU and all the analogues, therefore, cross reaction may still exist. Sample types: plasma, serum, tissue homogenates. Range: 9.38 - 600 mU/ml. Precision: Intra-Assay: CV<8% / Inter-Assay: CV<10%. Time: 4.5 hours