It is found in muscle, myocardium, brain, omentum, nerve, red blood cell and other animal tissues. The optimal pH=5.9-6.4, which can be activated by Ca2+, Mg2 or their mixture.
The content of adenylate deaminase (ADA) in lymphocytes is high. Tuberculous pleurisy Because of the stimulation of cellular immunity, lymphocytes increased significantly, so the ADA in pleural fluid was more than 45IU/L. It has high sensitivity in the diagnosis of tuberculous pleurisy. ADA was not increased in HIV patients with tuberculosis. 
