The effect of FGF-2 on proteoglycan accumulation and cell proliferation. Human articular chondrocytes were cultured in alginate beads with indicated treatments for 21 days before assaying for proteoglycan and DNA content. (A) Proteoglycan accumulation was assessed by dimethylmethylene blue (DMMB) assay, normalized by DNA content. (B) Cellular proliferation was quantified by total DNA content in beads from each treatment group. * P < 0.05; ** P < 0.01. FGF, fibroblast growth factor.