1,000 U Conjugation Grade Ammonium Sulfate Suspension Source: Calf Intestine Adenosine Deaminase: <=0.001% Concentration (37 C): >7500U/ml Phosphodiesterase: <=0.001% DNase, RNase, and Protease: None Specific activity (37 C, pH 10.5, DEA): >1500U/mg