Module 1-3 Flashcards
Name three chromophores
Quinoid, Azo, and Nitro groups
What is an amphoteric dye?
A dye that can be acidic or basic depending on the pH of the solution it is in
Natural stain that is used as a nuclear stain
Hematoxylin
Common basic auxochrome
Amino group
Acidic functional auxochromes
Hydroxyl, carboxyl, and sulphonic groups
What three components are need to make up a dye?
An origin (benzene ring), a chromophore and an auxochrome
What is the purpose of xylol in the first step of the hydrating process?
To get rid of wax
What is a dye combined with a mordant called?
A lake
What two processes must Hematoxylin go through in order to be a dye?
Oxidation and mordanting
4 main steps in the H&E stain
Nuclear stain, differentiate, blue and counterstain
What is hematoxylin oxidized to?
Hematin
How can hematoxylin be oxidized?
Either by atmospheric oxidation or by the use of chemical agents
What would nuclei look like if you over oxidized hematoxylin?
Reddish-brown/burgundy
2 main classifications of lakes
Ferric and aluminum
Which lake classification is unstable?
Ferric lakes
Which Hematoxylin dye is unstable and uses a ferric lake?
Weigert’s
The kind of lake used in Harris hematoxylin
Aluminum
Purpose of the bluing step in H&E
“locks” the hematoxylin in to the cells so it doesn’t leak out and it is more permanent
What two elements must be added to a benzene ring for it to become a dye?
Auxochrome and chromophore
Structure within a dye molecule that confers the property of color
Chromophore
Function of an auxochrome
Enables a dye to attach to the tissue elements of the opposite charge
What type of chemical structure is -N=N- termed when found as part of a dye molecule?
Chromophore
What is the substance that alters the colour of a metachromatic dye called?
Chromotrope
An intermediate substance required by some stains so that they may combine wtih a tissue structure
Mordant
