Results

Abstract

For a meaningful interpretation of the results reported in this study, it can be assumed that:

• 1. PTA-HC1 and PA-TCH-Ag both react with vicinal diol and α-aminoalcohol groups, which are only present in neutral carbohydrates and sialyl groups of the specimens investigated.

• 2. mPA-TCH-Ag probably stains only sialyl groups, but the selectivity of this reaction has not yet been completely proven.

• 3. Osmium-low ferrocyanide, the specificity of which is unknown, produces an electron-dense precipitate exclusively at tissue sites where methods of established specificity (PTA-HC1, PA-TCH-Ag) prove the presence of periodate-reactive carbohydrates. Moreover, osmium-low ferrocyanide leads to the same preservation of fine structure and osmiophilic staining of lipidic tissue components as conventional osmium postfixation without additives.