| Popis: |
Publisher Summary Many histological methods identify various polysaccharide-containing structures in microscopic preparations. This chapter discusses the classification of polysaccharides including polysaccharides, mucopolysaccharides, mucoproteins, glycoproteins, and glycolipids. The periodic-acid-Schiff reaction and other oxidizing reactions are described. Periodic acid is an oxidizing agent of specific activity. The rationale of the method is that certain chemical groups in the tissues are oxidized by the periodic acid, or other oxidant, and one of the reaction products is aldehyde. The aldehyde can then be identified by converting it to a colored complex. The most commonly used agent for identifying aldehyde is Schiff's solution (leucofuchsin), a colorless solution, which gives a bright magenta red color when it is combined with aldehyde. The general sequence of events is that the section is exposed to the oxidant for several minutes; then washed to remove excess oxidant, which might recolorize the leucofuchsin; exposed to the leucofuchsin for 15 to 30 minutes and then washed in a sulfite solution to remove excess colorless leucofuchsin that might subsequently become colored nonspecifically by oxidation on exposure to the atmosphere. The section can then be counterstained— if desired— dehydrated, cleared, and mounted. |
