2.4.3. Chondrogenic Differentiation Assay

A quantity of cells, numbering 2.5 × 10⁵, were transferred to a 15 mL conical tube, centrifuged at 200× g for 5 min at room temperature and resuspended with 1 mL of DMEM/F-12 basal media. Then the cells were again centrifuged and resuspended in 0.5 mL of chondrogenic differentiation media. After centrifugation the caps of the tubes were loosened, and the cells were incubated upright at 37 °C and 5% CO₂. The medium was replaced every 2–3 days, and, after 14–21 days, the chondrocyte pellet was fixed and prepared for frozen sectioning. The immunochemistry of chondrocytes, incubating the sections with the anti-hAggrecan antibody, was prepared according to the manufacturer procedures.