Fig. 1

Suspended synovium culture protocol. Human synovium was harvested during total knee arthroplasty from knee joints of patients with rheumatoid arthritis (RA; n = 8) and osteoarthritis (OA; n = 6). Approximately 1 g of synovium from each donor was suspended in each of six bottles that contained culture medium and a culture dish placed at the bottom of the bottle. After seven days of suspended synovium culture, three dishes were stained with 0.5% crystal violet and the suspended synovium was also examined histologically. After fourteen days of suspended synovium culture, the harvested cell numbers were evaluated from the remaining three dishes for each donor. The cells were passaged again and used for differentiation assays and analysis of surface epitope expression