An IgA-producing hybridoma cell line has been grown in two hollow-fiber reactors and one fluidized-bed reactor, using a serum-contg. medium and a protein-free medium. Comparisons have been made on the basis of product quantity (total IgA) and quality (active fraction, mol. wt. pattern). In hollow fiber reactors, IgA was produced at very high concns. but the fraction of active material was relatively low. [on SciFinder (R)]