Chapter 6: Nuclear and Cytoplasmic Staining Flashcards
What type of tissue is Harris hematoxylin used to stain?
Nuclei.
How do you “ripen” hematoxylin?
You expose it to oxygen.
What is the active staining molecule in ripened hematoxylin called?
Hematein.
What is the most important step in regressive hematoxylin staining?
The differentiation in acid alcohol because regressive hematoxylin staining is overstaining then differentiating.
Hematein is formed in Mayer hematoxylin solution by the addition of:
Sodium Iodate in order to “ripen” (oxidate) the hematoxylin.
How are mordants used in stains?
Oxidize the staining solution.
During H&E staining, if ammonia is incompletely removed by washing, the result may be:
Poor eosin staining.
The combination of a dye and a mordant is called a:
Lake.
Mercuric oxide was used in the original formula for Harris hematoxylin to:
Form hematein, but it was extremely toxic so it was replaced.
Which dye can demonstrate DNA?
The Feulgen reaction as well as methyl green.
T/F: Weigert is considered an Iron hematoxylin.
True.
What kind of hematoxylin is not readily decolorized with acidic solutions?
Iron hematoxylins, such as Weigert.
Why are natural resins hardly used for mounting sections?
Natural resins such as Canada balsam and gum dammar are slightly acidic and cause tissue fading after several years.
What kind of stain requires the use of an aqueous mounting media?
Oil red O so it doesn’t disrupt the lipid laden macrophages.
What type of metal salt serves as the mordant in Weigert hematoxylin?
Iron
Why is acetic acid added to Harris hematoxylin?
To make nuclear staining more specific.
What is a dye that can be substituted for hematoxylin in routine staining?
Celestine blue can be substituted for hematoxylin with identical results.
What is a good example of a polychrome stain?
Giemsa.
What is a polychrome stain?
A polychrome stain is a compound dye or dye mixture containing components of different colors.
What cellular structure is stained rose by the methyl green-pyronin (MGP) technique?
RNA.
The chemical group in dyes that confers the property of color is called a:
Chromophores.
What is an auxochrome?
Ionizing groups that confer to the tissue.
What is formed when hematoxylin is subjected to the action of sodium iodate?
Hematein.
What is heterochromatin stained by?
Heterochromatin is the substance in the nucleus that is stained by hematoxylin.