Electron microscopy : use of lectin-peroxidase prior to embedding

Pre-embedding lectin cytochemistry is one in a range of approaches used for analyzing the subcellular localization of glycoconjugate-classes, and thus enables the determination of the carbohydrate composition of cellular compartments. At the cell's surface, the carbohydrate composition is important in defining cell types; changes in these components are associated with cellular differentiation, maturation, and neoplastic transformation (1-4) Here lectins provide well-defined reagents for the identification of cell types and for the study of these dynamic processes (5-7). Intracellularly, lectins have been used in multiple studies for the analysis of the biosynthetic and endocytic pathway. Such lectin cytochemistry has helped to unravel single steps of the glycosylation process and to elucidate topographical aspects of glycosylation (8-16) Interpreting the lectin binding patterns, it has to be borne in mind that the determinants recognized by a lectin may be common to several different glycoproteins and glycolipids.