William J Feathers, Age 493021 Pleasant View Ave, Maryville, TN 37803

5578201, Nov 26, 1996

May 26, 1995

8/451353

Charles F. Collier - Wilmington DE
Brian A. Deane - Wilmington DE
William E. Feathers - Cochranville PA
Robert A. King - Hockessin DE
Alexander D. Kopatsis - Wilmington DE
Thomas P. Ladisch - Alburtis PA
Peter M. Mrozinski - Hockessin DE
Norman P. Pih - Newark DE

E. I. du Pont de Nemours and Company - Wilmington DE

B01D 1104

210142

A reusable apparatus for multiphase, multistage countercurrent liquid separation is presented. The apparatus is particular useful in progressive multistage separation of target microorganisms from background organisms and materials with precise transfer, air exclusion, homogeneous mixing, isolation from the ambient atmosphere, in the absence of valves and at ow cost. The structure has at least one chamber in which a piston-like sliding bottom is sealingly moved or braked and includes internal structure for mixing, preferably a magnetic-stainless steel ball which can be reciprocated from the outside to mix the liquid contents. Motion of the bottom is limited by stops. A number of ways to actuate the apparatus are taught.