Description; Application; Protein-AQUA™ is a powerful, enabling technology that facilitates focused, quantitative studies of not only specific protein expression, but specific amino acid modification as well, using stable-isotope–labeled peptides and mass spectrometry.; Legal Information; This method was developed by Dr. Steve Gygi and colleagues at Harvard Medical School. Limited use of this method is permitted under a licensing arrangement with Harvard Medical School.; AQUA is a trademark of Harvard Medical School