It is recommended to take 2~3 samples with expected large difference to do pre-experiment before formal experiment and dilute the sample according to the result of the pre-experiment and the detection range ( 1.21-40 U/g fresh weight ).The recommended dilution factor for different samples is as follows (for reference only): Sample type Dilution factor, 20% Mouse brain tissue homogenate 20% Rat heart tissue homogenate 20% Rat liver tissue homogenate 20% Mouse kidney tissue homogenate 20% Rat lung tissue homogenate 1. Note: The diluent is normal saline (0.9% NaCl) or PBS (0.01 M, pH 7.4).