Determination of intracytoplasmic filaments in the chondrocytes of articular cartilage.

Intracytoplasmic filaments were demonstrated in the chondrocytes of articular cartilage of cattle at 82 days post partum and at 3 and 4 years of age using transmission electron microscopy and immunocytochemistry. Samples of cartilage for electron microscopy were processed in a standard way. Immunocytochemical procedures were performed with semithin sections made from the material prepared for electron microscopy after embedding medium and osmium compounds had been eliminated. Vimentin filaments were demonstrated by means of anti-vimentin monoclonal antibody visualized by peroxidase-labelled immunoglobulin. Both techniques showed that intracytoplasmic filaments were situated around the nucleus and only occasionally at the cell periphery, e.g. in cell projections.