Fig. 2. Chondrogenesis in pellet cultures. (a,b) Immunoreactivity for type II collagen at 7 days (a) and 14 days (b) of culture. Notice the diffuse staining, which spares a thin rim of matrix at the periphery of the tissue `bead'. (c) Growth in size of the tissue bead over time. A plateau is reached at day 14. The arrow indicates the switch to medium conducive to in vitro mineralization. Each point represents the mean of the cross-sectional diameter measured in three samples per time point. Bar, 125 µm.