PAS staining of eosinophils in semi-thin sections of bone marrow embedded in glycol methacrylate

The usual periodic acid-Schiff (PAS) reaction of glycosaminoglycans is applicable to paraffin embedded material. A modification for water-miscible methacrylate embedded tissue suitable for correlative light and electron microscopic studies, which makes it possible to find the same stained cell in a semi-thin tissue section, is described. Eosinophil leukocytes in semi-thin sections from bone marrow were verified by electron microscopy after staining with the PAS reaction. Immature eosinophil leukocyte granules reacted with and without previous salivary treatment. This method facilitates the search for localization of glycosaminoglycans in scattered blood cells.