IMMOBILIZATION OF NONANCHORAGE-DEPENDENT CELLS

Nonanchorage-dependent cells are immobilized for cell culturing or the production of cell products, by contacting a medium comprising the cells with floc formed by the combination of positively and negatively charged ion exchange resins having an average particle size ranging from about 0.01 to about 1.5 micrometers. The flocs may be formed either prior to contact with the cells or may be formed in-situ in the cell-containing medium upon separate addition of the resins, preferably by first adding the positively charged resin followed by the negatively charged resin. The resin floc operates as a microcarrier for the cells and the immobilized nonanchorage-dependent cells may be cultured in suspension and maintained in perfusion culture with substantially reduced cell loss and without the need for specialized filters or other equipment.