Figure 4.

Calcium deposition by matrix vesicles and apoptotic bodies. Matrix vesicles isolated from articular cartilage and apoptotic bodies prepared from SNP-treated chondrocytes were isolated and incubated in calcifying solution containing ⁴⁵Ca. Crystalline deposits were solubilized in HCl, and radioactivity was quantified by liquid scintillation counting. Assay controls include the omission of ATP [ATP(−)] and negative control without the addition of matrix vesicles or apoptotic bodies [sample(−)].