Module 1: General Staining Theories Flashcards
What is the purpose of xylene in the first step of bringing to water?
To remove the wax
What three components are needed to make up a dye?
Origin, chromophore, auxochrome
What is the common basic auxochrome?
Amino group
Name the natural stain that is used as a nuclear stain
Hematoxylin
What is an amphoteric dye?
A dye that can be acidic or basic depending on the pH of the solution it is in
Name three chromophores
Quinoid, azo, nitro
What is a dye combined with a mordant called?
Lake
Name two functional acidic auxochromes
Carboxyl, hydroxyl
Name the three most common chromophore groups
Quinoid, nitro, azo
Two classifications of metallic impregnation
Argentaffin, argyrophil
Name the two main theories used to explain the ways in which dyes interact with tissues to produce a coloured end product
Physical and chemical
True or false: Benzene is the most common aromatic compound
True
What term describes the structure within a dye molecule which confers the property of a colour?
Chromophore
What are the staining characteristics of a chromogen?
It is coloured and has no tissue affinity
What is the function of an auxochrome?
To enable a dye to attach to tissue
Classification of dyes by their auxochrome group is based on what?
Charge of the dye ion
What type of stain is formed by combining an acid and a basic dye?
Neutral
When an amphoteric dye is in a solution below its isoelectric point it behaves like which type of dye?
Basic dye
When should quality control slides be run when staining tissue?
With each batch of patient slides
Which characteristic must a lysochrome used in a preferential solubility staining method for lipids possess?
Strongly coloured
What is a substance which alters a metachromatic dye called?
Chromotrope
List 3 reasons why metallic impregnation cannot be classified as true staining
No chromophore groups
Silver is deposited around not wishing the structure
Silver solutions are heterogeneous
What differentiates an argentaffin method from an argyrophil method?
In an argentaffin method tissue components reduce the silver directly
