Chapter 7: Carbohydrates

Question 1

Glycogen is best shown with the demonstration of which stain?

Answer 1

PAS with or without diastase. The Diastase will dissolve glycogen and the lack thereof will just stain it.

Question 2

What stain will demonstrate amyloid?

Answer 2

The Congo Red stain.

Question 3

What does the Schiff reaction demonstrate?

Answer 3

Aldehydes.

Question 4

What would be a good tissue type to use as a control for the Mayer mucicarmine stain?

Answer 4

Appendix or any type of tissue that shows an excess of goblet cells.

Question 5

What would be a good tissue type to use as a control for glycogen?

Answer 5

Liver or also cervix.

Question 6

To increase the specificity for amyloid, Congo red stains should be examined under what type of microscopy?

Answer 6

A polarizing microscope.

Question 7

What is the best fixative for glycogen?

Answer 7

Absolute alcohol.

Question 8

How is periodic acid used in the PAS technique?

Answer 8

Periodic acid oxidizes the aldehyde groups.

Question 9

Why would a crystal violet stain be used for Amyloid?

Answer 9

It is a polychromatic stain and this would cause the amyloid to be very well visible under a polarized microscope.

Question 10

Acid mucopolysaccharides are demonstrated by which stain?

Answer 10

Alcian blue.

Question 11

The reliability of the PAS reaction may be checked by adding what to a small aliquot of the Schiffs reagent?

Answer 11

Formaldehyde, it should turn the Schiffs bright pink.

Question 12

The fluorescent dye for the demonstration of amyloid is:

Answer 12

Thioflavin.

Question 13

What does the Alcian blue stain performed at pH of 0 demonstrate?

Answer 13

Sulfated acid mucopolysaccharides ONLY.

Question 14

What color will the substances stained positive during the colliodal iron stain be?

Answer 14

Blue.

Question 15

How is Schiffs reagent created?

Answer 15

It is a reduced solution of basic fuchsin.

Question 16

What does diastase digestion increase specificity for?

Answer 16

Glycogen because it is digested.

Question 17

Colloidal iron is used for the demonstration of:

Answer 17

Acid mucopolysaccharides.

Question 18

What is another way to demonstrate glycogen besides the PAS?

Answer 18

The Best Carmine stain.

Question 19

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:

Answer 19

Glycogen, it is the only substance that is sensitive to diastase.

Question 20

What kind of fungi is well demonstrated with the colloidal iron stain?

Answer 20

Cryptococcus neoformans because it has a mucinous capsule.

Question 21

T/F: Glucose, sucrose and other oligopolysaccharides can be easily demonstrated in tissue sections.

Answer 21

False, they are extremely soluble.

Question 22

T/F: Hyaluronidase is used to digest some connective tissue mucins.

Answer 22

True.

Question 23

T/F: The Alcian blue stain should be performed at 1.5 pH.

Answer 23

False, the routine pH is 2.5

Question 24

T/F: Good Schiffs reagent should be light pink.

Answer 24

False, good Schiffs should be clear or straw colored.

Question 25

T/F: The end product in a colloidal iron is a Prussian blue.

Answer 25

True.

Question 26

T/F: Amyloid shows a yellow birefringence following staining with Congo Red.

Answer 26

False, it shows an apple green birefringence.

Question 27

T/F: Glutaraldehyde is one of the recommended fixatives for the PAS reaction.

Answer 27

False, it will react with the Schiffs creating a false positive.

Question 28

T/F: Pas may show a false positive following chromate-containing fixatives.

Answer 28

False, the PAS reaction will be weak.

Question 29

T/F: Glycogen-containing tissue fixed in Bouin solution may show resistance to diastase digestion.

Answer 29

True.

Question 30

T/F: The addition of acid to the crystal violet staining solution reduces background staining.

Answer 30

True.

Question 31

T/F: 4-6micron sections are recommended for crystal violet stains.

Answer 31

True.

Question 32

What structure is stained red in a Muci?

Answer 32

Goblet cells, specifically the mucin in them.

Question 33

No staining of the glomerular basement membrane can be seen microscopically on a control section of kidney. What happened?

Answer 33

Inadequate oxidation will cause a weak PAS reaction.

Question 34

Marked nonspecific staining is noted on a section stained with the PAS technique. This could be the result of:

Answer 34

Previous fixation in glutaraldehyde.

Question 35

Very weak staining is noted on a PAS stained control liver section. One problem solving action would be to:

Answer 35

Check a sample of Schiffs reagent with a few drops of formaldehyde to make sure that it still works.

Question 36

Sections of small intestine show orange goblet cells that are partially obscured by the yellow background. What happened?

Answer 36

The tissue was overstained with Metanil yellow.

Question 37

Control sections stained with Congo red only show yellow and no green birefringence. What happened?

Answer 37

The sections were cut too thin, they need to be cut between 8-10microns.

Question 38

Muscle that histologically contains cytoplasmic cross-striations and has multiple nuclei located at the edge of the fibers is classified as:

Answer 38

Skeletal muscle fibers.

Question 39

An effective counterstain following some silver impregnation procedures is:

Answer 39

Light green.

Question 40

The Fontana-Masson technique may be used to stain:

Answer 40

Melanin.

Question 41

What regressive staining is a method for demonstrating connective tissue component?

Answer 41

The Verhoeff-Van Gieson.

Question 42

What is the differentiating solution in the Holzer method for glial cells?

Answer 42

Aniline oil-chloroform.

Question 43

What staining procedure is preferred for demonstrating intracytoplasmic DNA-type viral inclusions in tissue?

Answer 43

The Feulgen stain.

Question 44

What is a solvent that is commonly used in oil red O and Sudan black B solutions to prevent the loss of lipids?

Answer 44

Propylene glycol.

Question 45

In the Verhoeff- van Gieson technique for demonstrating elastic fibers, how long should the staining solution be used?

Answer 45

It can be used for only a few hours before it has to be remade.

Question 46

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?

Answer 46

The Truant auramine-rhodamine procedure.

Question 47

Microscopic inspection of a PAS stained control section for fungi reveals very palely stained fungal organisms. What happened?

Answer 47

The schiff reagent has been overused.

Question 48

What are some examples of natural dyes?

Answer 48

Hematoxylin, carmine and orcein.

Question 49

What is a chemical that will bleach melanin?

Answer 49

Potassium permanganate.

Question 50

Microscopic review of a section stained with the Warthin-Starry (Steiner) technique shows the spirochetes stained yellow. What happened?

Answer 50

Underdevelopment in the heated solution.