RHEUMATOID AND NORMAL SYNOVIAL TISSUE IN LONGTERM CULTURE - EVIDENCE OF CELL HETEROGENEITY AND AN APPROACH TO QUANTITATION OF POPULATIONS AND EFFECT OF PASSAGE
Longterm monolayer cultures of cells [human] derived from explants of 21 normal and 31 rheumatoid synovial tissue specimens were morphologically heterogeneous. The cultures were defined according to their cell size and their buoyant density as determined by separation on Ficoll density gradients. Changes in these populations occurred with each passage of the cell lines. These findings emphasize the importance of using cultures of the same cultural age and passage for any comparative study. The techniques described are useful for separating and defining the populations present in synovial tissue cultures.