A Human ACE Quantikine( ELISA kit is available from R&D Systems. Angiotensin I Converting Enzyme is known for its role in blood pressure control and water and salt metabolism. ACE is also involved in immunity, reproduction and neuropeptide regulation due to its localization and specificity. This assay has a sensitivity of 0.019 ng/ml, a dynamic range from 0.78 to 50 ng/ml, and is fully validated for serum, plasma, saliva and cell culture supernatants.