Abstract: An improved method for the rapid separation of the MM and MB creatine kinase isoenzymes is provided. The method involves the use of an ion exchange support material comprising porous glass beads having a stationary phase coupled to the surfaces thereof through an intermediate coupling agent. The intermediate coupling agent is preferably a silane coupling agent constituted by an organosilane with a silicon functional group capable of bonding to the surfaces of the glass beads and an organic functional group capable of bonding to the stationary phase. Less preferably, the coupling agent may be formed from a Grignard reagent of the formula RMgX where R is lower alkenyl and X is halogen.