Activating hydroxyl groups of polymeric carriers using 4-fluorobenzenesulfonyl chloride.

4-Fluorobenzenesulfonyl chloride (fosyl chloride), due to the strong electron-withdrawing property of its fluoride atom, is found to be an excellent activating agent for the covalent attachment of biologicals to a variety of solid supports (e.g. functionalized polystyrene microspheres, Sepharose beads, or cellulose rods and hollow fibers). This reagent reacts rapidly with primary or secondary hydroxyl groups, at ambient temperature and pressure, to form 4-fluorobenzenesulfonate leaving groups. The activated solid support can be used immediately or preserved for several months without loss of activity by freeze-drying or by storage at 4 degrees C in aqueous solution at pH 5. Enzymes, antibodies, avidin, and other biologicals can be covalently attached to the activated solid phase with excellent retention of biological function. Potential therapeutic applications of the fosyl chloride chemistry for bioselective separation of human lymphocyte subsets from whole blood and tumor cells from bone marrow are presented.