The US Patent and Trademark office has awarded AxCell Biosciences US patent 6,309,820 entitled “Polypeptides Having a Functional Domain of Interest and Methods of Identifying and Using Same.” The patent, with 9 claims, covers the company’s method for identifying SH3 domain-containing proteins from human cDNA expression libraries, and is the first patent awarded for AxCell’s Cloning of Ligand Targets proteomics technology.