H+E stains Flashcards
What are the principle dyes of H+E?
Hematoxylin and Eosin
what is Ehrlichs Hematoxylin
Positively charged regressive nuclear staining dye
What is Mayers Hematoxylin
Positively charged regressive nuclear staining dye
- Also works as a progressive counterstain
What is Weigerts Hematoxylin
Positively charged progressive nuclear counterstaining dye
- more resistant to acidic conditions
Does hematoxylin need to be oxidised?
Yes
Ehrlichs = Light/air for 3-4 months
Mayers = Sodium Iodate
Weigerts = Light/air 1 month
What is a Mordant?
Mordant = bite
Mordants are (typically metal salts) compounds used to enhance the binding abilities of dyes
What mordants are used for hematoxylin stains?
Ehrlichs = Aluminium
Mayers = Aluminium
Weigerts = Iron
What is Eosin? what does it stain?
Negatively charged counterstain for hematoxylin stains.
Stains RBC, Collagen, Muscle, and Cytoplasm
Function of H+E stains
To display the general morphology of tissue samples
Histochemical Basis of H+E stains
Ionic charge/pH
Positive Hx binds to negative structures (Nuclei)
Negative Eosin binds to positive structures (RBC, Muscle, cytoplasm, etc)
What is differentiation?
Regressive stains are initially over-stained, differentiation decreases the amount of staining back to a nominal amount by releasing unwanted stain.
purpose of acid alcohol
Differentiation
Purpose of Ammonia
To “blue” the stain
What is “Blueing”
When ammonia is added to the stain (typically after differentiation) it turns the acidic sites alkaline and changes the stain from red to blue. this change also solidifies the Hx stain.
Makes the hematoxylin insoluble in water
What is hematin
Oxidised hematoxylin
What are the colours of each stained structure
Nuclei = Blue
RBC = Orangeish
Muscle/Fibrin = Red
Everything else = hues of pink
What is hematoxylin derived from
The heart wood of the Haematoxylum campechianum tree found predominantly within mexico and central america
