Pathology PRACTICALS 1-3 + IHC Flashcards
Correct sequence for PAS staining?
Dewax , periodic acid , Schiff’s reagent , haematoxylin , dehydrate
What are the 3 types of carbohydrate tests?
Direct staining using cationic dyes eg. Alcian blue
Direct staining using chemical tests (eg. PAS)
Use of lectins eg. Concanavalin A
What does periodic acid do?
Oxidises glycols to aldehydes
What is Schiff’s reagent made of?
Pararosaniline and sodium metabisulphite
What is HER2?
Human Epidermal growth factor Receptor 2
What are mucosubstances?
Polysaccharides
Proteoglycans
Glycoproteins
Why is eosin not used as a counterstain?
The pink stain of eosin masks the pink/red colour of PAS
What is over expression of HER2 mostly due to?
Increased gene amplification
Haematoxylin and Eosin
Basic or Acidic?
Haematoxylin - BASIC
Eosin - ACIDIC
What is a mordant?
Alters specificity of staining
Negatively charged ionic metals
Which mordant does Harris’s haematoxylin use?
Aluminium salts
The binding of haematoxylin to a tissue involves which mechanism?
Coulombic attractions
What are the different types of inflammation?
Serous - example is blister
Suppurative - characteristic is pus
Catarrhal
Mucopurulent
Pseudomembranous
Fibrinous
Hemorrhagic
What is a trichrome stain?
Used to distinguish collagen from muscle
What is MSB?
A trichrome stain
Martius Scarlet Blue
Used to demonstrate fibrin
