Incident light microscopy of surfaces of plastic embedded hard tissues

To eliminate sectioning artefacts, we devised a method for the preparation of surfaces of plastic embedded hard tissues and their examination by incident light fluorescence microscopy. Flat surfaces produced by cutting on a microtome or using a low-speed saw were stained with dyes in aqueous solutions. Best results were obtained in tissues embedded in glycol-methacrylate. This polymer allowed good penetration of the dyes and its optical properties render cutting defects invisible with the present method. The relationship between hard and soft tissues was well preserved and the integrity of the mineralized component maintained. Cellular details and the distinction between osteoid and bone could be clearly/demonstrated. The procedure is simple, rapid and produces good results even in instances when histological sectioning is unsatisfactory.