Cartilage explant cultures.

To investigate chondrocyte biology in an organized structure, limb explant cultures have been established that allow the cultivation of the entire cartilaginous skeletal elements. In these organ cultures, the arrangement of chondrocytes in the cartilage elements and their interaction with the surrounding perichondrium and joint tissue are maintained. Chondrocyte proliferation and differentiation can thus be studied under nearly in vivo conditions. Growth factors and other soluble agents can be administered to the explants, and their effect on limb morphogenesis, gene expression, and cell-matrix interactions can be studied. Co-treatment with distinct growth factors and their inhibitors as well as use of transgenic mice will allow one to decipher the epistatic relationship between different signaling systems and other regulators of chondrocyte differentiation. Here we describe the protocol to culture cartilage explants ex vivo and discuss the advantages and disadvantages of the culture system.