METHOD AND APPARATUS FOR STIRRING PARTICLES IN SUSPENSION SUCH AS MICROCARRIERS FOR ANCHORAGE-DEPENDENT LIVING CELLS IN A LIQUID CULTURE MEDIUM

摘要

Stirring apparatus for stirring particles in a liquid medium comprising a cylindrical stirring vessel (1) having a stirring rod (2) extending within the vessel to stir its contents. The rod (2) has a bulbous tip (2A) which describes an orbital path in the vessel to sweep out an annular trough or channel (5) formed in the bottom of the vessel. The annular trough or channel (5) is contoured in section (6) to follow the flow lines set up in the medium by secondary motion stirring effects. In this way accumulation of particles due to the secondary motion, which would otherwise occur at the corners and centre of the bottom of the vessel, is avoided. The apparatus is advantageously useful in cell culture research particularly for stirring microcarriers in a liquid culture medium because it becomes possible to maintain the microcarriers in uniform suspension at lower stirring speeds than heretofore possible thus avoiding damage to the growing cells and improving overall cell yield.