Chapter 7: Carbohydrates Flashcards
Glycogen is best shown with the demonstration of which stain?
PAS with or without diastase. The Diastase will dissolve glycogen and the lack thereof will just stain it.
What stain will demonstrate amyloid?
The Congo Red stain.
What does the Schiff reaction demonstrate?
Aldehydes.
What would be a good tissue type to use as a control for the Mayer mucicarmine stain?
Appendix or any type of tissue that shows an excess of goblet cells.
What would be a good tissue type to use as a control for glycogen?
Liver or also cervix.
To increase the specificity for amyloid, Congo red stains should be examined under what type of microscopy?
A polarizing microscope.
What is the best fixative for glycogen?
Absolute alcohol.
How is periodic acid used in the PAS technique?
Periodic acid oxidizes the aldehyde groups.
Why would a crystal violet stain be used for Amyloid?
It is a polychromatic stain and this would cause the amyloid to be very well visible under a polarized microscope.
Acid mucopolysaccharides are demonstrated by which stain?
Alcian blue.
The reliability of the PAS reaction may be checked by adding what to a small aliquot of the Schiffs reagent?
Formaldehyde, it should turn the Schiffs bright pink.
The fluorescent dye for the demonstration of amyloid is:
Thioflavin.
What does the Alcian blue stain performed at pH of 0 demonstrate?
Sulfated acid mucopolysaccharides ONLY.
What color will the substances stained positive during the colliodal iron stain be?
Blue.
How is Schiffs reagent created?
It is a reduced solution of basic fuchsin.
What does diastase digestion increase specificity for?
Glycogen because it is digested.
Colloidal iron is used for the demonstration of:
Acid mucopolysaccharides.
What is another way to demonstrate glycogen besides the PAS?
The Best Carmine stain.
Adjacent sections are stained with PAS, one with and one without diastase digestion. A positive on the one with no digestion and a negative on the diastase section indicates the presence of:
Glycogen, it is the only substance that is sensitive to diastase.
What kind of fungi is well demonstrated with the colloidal iron stain?
Cryptococcus neoformans because it has a mucinous capsule.
T/F: Glucose, sucrose and other oligopolysaccharides can be easily demonstrated in tissue sections.
False, they are extremely soluble.
T/F: Hyaluronidase is used to digest some connective tissue mucins.
True.
T/F: The Alcian blue stain should be performed at 1.5 pH.
False, the routine pH is 2.5
T/F: Good Schiffs reagent should be light pink.
False, good Schiffs should be clear or straw colored.
T/F: The end product in a colloidal iron is a Prussian blue.
True.
T/F: Amyloid shows a yellow birefringence following staining with Congo Red.
False, it shows an apple green birefringence.
T/F: Glutaraldehyde is one of the recommended fixatives for the PAS reaction.
False, it will react with the Schiffs creating a false positive.
T/F: Pas may show a false positive following chromate-containing fixatives.
False, the PAS reaction will be weak.
T/F: Glycogen-containing tissue fixed in Bouin solution may show resistance to diastase digestion.
True.
T/F: The addition of acid to the crystal violet staining solution reduces background staining.
True.
T/F: 4-6micron sections are recommended for crystal violet stains.
True.
What structure is stained red in a Muci?
Goblet cells, specifically the mucin in them.
No staining of the glomerular basement membrane can be seen microscopically on a control section of kidney. What happened?
Inadequate oxidation will cause a weak PAS reaction.
Marked nonspecific staining is noted on a section stained with the PAS technique. This could be the result of:
Previous fixation in glutaraldehyde.
Very weak staining is noted on a PAS stained control liver section. One problem solving action would be to:
Check a sample of Schiffs reagent with a few drops of formaldehyde to make sure that it still works.
Sections of small intestine show orange goblet cells that are partially obscured by the yellow background. What happened?
The tissue was overstained with Metanil yellow.
Control sections stained with Congo red only show yellow and no green birefringence. What happened?
The sections were cut too thin, they need to be cut between 8-10microns.
Muscle that histologically contains cytoplasmic cross-striations and has multiple nuclei located at the edge of the fibers is classified as:
Skeletal muscle fibers.
An effective counterstain following some silver impregnation procedures is:
Light green.
The Fontana-Masson technique may be used to stain:
Melanin.
What regressive staining is a method for demonstrating connective tissue component?
The Verhoeff-Van Gieson.
What is the differentiating solution in the Holzer method for glial cells?
Aniline oil-chloroform.
What staining procedure is preferred for demonstrating intracytoplasmic DNA-type viral inclusions in tissue?
The Feulgen stain.
What is a solvent that is commonly used in oil red O and Sudan black B solutions to prevent the loss of lipids?
Propylene glycol.
In the Verhoeff- van Gieson technique for demonstrating elastic fibers, how long should the staining solution be used?
It can be used for only a few hours before it has to be remade.
A Ziehl-Neelsen procedure is done on a lung granuloma, but no acid-fast organisms are demonstrated. It would be wise to verify the absence of these organisms by using which stain?
The Truant auramine-rhodamine procedure.
Microscopic inspection of a PAS stained control section for fungi reveals very palely stained fungal organisms. What happened?
The schiff reagent has been overused.
What are some examples of natural dyes?
Hematoxylin, carmine and orcein.
What is a chemical that will bleach melanin?
Potassium permanganate.
Microscopic review of a section stained with the Warthin-Starry (Steiner) technique shows the spirochetes stained yellow. What happened?
Underdevelopment in the heated solution.
