There is an ongoing need to isolate and purify ceIls in bivalve mollusc disease research. Many separation techniques differentiate cells solely by a single factor and usually require additives in the medium that may damage live cells. Centrifugai elutriation is a technique that separates particles by size and density simultaneously and can be conducted in physiological media without additives. Living cells can be separated without chemical damage and, because the procedure can be conducted aseptically, cells can be maintained in vitro after elutriation. A description of the technique, methods to determine flow rates and rotor speeds, and a preliminary separation of oyster hyalinocytes is presented