Abstract
Human synovial cells were grown in a semi-synthetic tissue culture medium which excludes embryo extract. Supported by the semi-synthetic medium, the synovial cells produced a mucopolysaccharide believed to be hyaluronic acid on the basis of nondialyzable hexosamine content and susceptibility to hydrolysis by both testicular and bacterial hyaluronidase. Culture morphology, behavior and pattern of mucopolysaccharide production are described.