This method was developed by Dr. Steve Gygi and colleagues at Harvard Medical School [Stemmann O, Zou H, Gerber SA, Gygi SP, Kirschner MW; Dual inhibition of sister chromatid separation at metaphase, Cell 2001, Dec 14, 107: 715-726] and is the subject of both U.S. and PCT Patent Applications. Limited use of this method is permitted under a licensing arrangement with Harvard Medical School.