The separation of calli and recovery of extracellular polysaccharides (TPS) by filtration from culture broth of Polianthes tuberosa was studied. In the dead-end filtration operated under a constant pressure with a laboratory-scale instrument, the formation of a filter aid precoat layer improved the optical transmittance of the filtrate. Filtration resistance of the precoat layer increased in proportion to the amount of filter aids in the precoat layer in the range of 0.48-2.7 kg/m(2). Average specific filtration resistance of the cake layer was almost constant when the ratio of filter aid to callus concentration in feed slurry was 60-89. A filtration test with a bench-scale filter press was performed in a dead-end mode at a constant feed flow rate, based on the operational guidelines and running conditions determined in the laboratory-scale filtration tests. As a result, desirable filtration performance was achieved, giving a filtrate of over 95% optical transmittance associated with TPS recovery of almost 100%, up to a determined treatment volume of 0.22 m(3)/m(2).