Michael H. Gelb studied chemistry and biochemistry as an undergraduate at the University of California at Davis. His Ph.D. studies with Stephen G. Sligar at Yale University led to a better understanding of the catalytic mechanism of cytochrome P450. As an American Cancer Society Postdoctoral Fellow in the laboratory of the late Robert H. Abeles at Brandeis University, Gelb studied a variety of mechanism-based inactivators of serine proteases and developed fluorinated ketones as tight-binding inhibitors of several classes of proteases. In 1985 Gelb became a faculty member in the Departments of Chemistry and Biochemistry at the University of Washington. Major breakthroughs in the group include the development of methods to properly analyze the action of enzymes on membrane surfaces, the discovery of protein prenylation (farnesylation and geranylgeranylation) in mammalian cells (together with John A. Glomset), the development of Isotope-Coded Affinity Tags (ICAT reagents) for proteomic applications (together with Ruedi Aebersold), and the development of newborn screening for lysosomal storage diseases by mass spectrometry.