Histology for CSMLS Latest 2024 Graded A+

Histology for CSMLS Latest 2024 Graded A+ 3 types of Carbohydrates demonstrated in tissues Glycoproteins, polysaccharides, proteoglycans What stain is used for glycogen? PAS - because glycogen has vicin diols Where is glycogen found in the body? Liver, skeletel and cardiac muscle, hair follicles, vaginal and ectocervical epithelium, mesothelium cells, neutrophils and megakaryocytes. What accounts for the staining reaction of Glycoproteins? sialic acid goups and vicin diols (PAS), also contains carboxyl acid group (Alcian Blue). Where are glycoproteins in the body? Most are associated with epithelial tissues. They are classified as either neutral or acidic depending on whether they contain a Sulphate or Carboxylate residues. What do neutral glycoproteins lack? Where do you see them? They lack bother Carboxylate (COOH) and Sulphate (SO3H). They are found in goblet cells in the stomach as well as paneth cell granules in the small bowel. Where are acidic glycoproteins that contain only COOH found in the body? They can be found submaxillary gland, small intestine, fetal extracellular matrix, upper part of colonic crypts, sublingual gland. Where are acidic glycoproteins that contain both COOH and SO3H found in the body? Mainly found in colonic goblet cells. What are Proteoglycans (Glycosaminoglycans)? They are large, unbranched carbohydrates with small poly peptide chains. Where in the body can you find Proteoglycans? Connective tissues such as cartilage, bone, tendons, ect. Referred to as acid or neutral mucins. What compound reacts with Cationic dyes in a Carbohydrate? The acid containing sugar (COOH or SO3H) What are the routine stains for Carbohydrates ? PAS, Alcian Blue Muricarmine, Colloidal iron, Metachromasia, Lectins 2 main steps in PAS method? Oxidize carbohs with periodic acid to create aldehydes. Demonstrating the resulting aldehydes with Schiffs reagent. Potential false PAS positives ? When glutaraldehyde is used as a fixative, and only some lipids found in frozen sections. What does Schiffs reagent do in PAS? It is attracted to an reacts with aldehydes. Some Proteoglycans contain vicin diols but do not stain with PAS, why ? Because the periodate ion is repelled by the COO and SO3, therefore oxidation does not occur and the aldehydes are not exposed. How do you distinguish staining between glycogen and neutral glycoproteins ? By using enzymes such as diastase or amylase which digest glycogen. The remaining stain after treatment is therefor neutral glycoproteins. What kind of dye stains acidic substances ? Cationic dyes. What type of dye is Alcian blue? Cationic What are the 2 types of Alcian blue stain? pH of 1.0 and 2.5 What are the results of Alcian blue 2.5? Both sulfated and