PREPARATION OF HUMAN ARTICULAR-CARTILAGE FOR SCANNING ELECTRON-MICROSCOPY

The adequacy of surface preservation obtained with the techniques [16], was judged subjectively: 1st, by the reproducibility of secondary electron images of normal cartilage and 2nd, by comparing the results with those obtained by reflected light microscopy of the fresh unfixed cartilage surface over a magnification range of .times. 20-.times. 240. Adequate surface preservation was confirmed when cartilage surfaces were dehydrated through ethanol to propylene oxide and vacuum dried; dehydrated through amyl acetate and quenched in Freon before freeze-drying; dehydrated and passed through amyl acetate at low temperature before freeze-drying. Valuable information can be obtained from different specimens by varying the technique of preparation. At different ages, different surface features are best preserved. In a systematic study it was essential to adopt a uniform preparative method and to control the results by reflected light microscopy. Even with the most perfect preparation, the surface appearances cannot be identical with those that function under load in vivo.