W7- Lecture 35.2- Histology- Staining Flashcards
What is the purpose of staining ?
Allows examination of tissues by light microscopes
Because cells are translucent
Describe using Haematoxylin and eosin (H&E) as a stain
What it stains / what colour
Haematoxylin: cationic dye (+ charge) that binds to negatively charged (acidic) structures in the cell.
Nucleus = Blue
Eosin: anionic dye (- charge) adheres to basic structures in the cell. Amine groups (NH3+) on proteins make
cytoplasm = Pink
Describe using DAPI as a stain
What it stains / what colour
Process
Bind to A-T in DNA
Can pass through intact membranes (alive or dead cells )
Fluorescent stain- nucleus blue
First image excitation of electrons and collection through emission filter
X2
Very tight excitation spectrum
Describe using Alcian blue as a stain
What it stains/ colour
Any combinations?
Mucin Stains Acid mucins - blue Cartilage -blue Proteoglycans- blue Nuclei- red/black
Can be used with H&E and with van gieson stains
Describe using Oil Red O as a stain
What it stains/ colour
When to use
Fat- brilliant red
Nuclei - blue
Stains fat in unfixed frozen sections
- should not be processed with alcohol as this may remove fat content from cell
Describe using Millers Sirius Red as a stain
What it stains/ colour
Describe phase contrast and the use of this
Elastin Dark purple/ Black
Collagen Red/ Pink
Collagen is birefringfent (under phase contrast)
Depending on thickness and size
New and smaller fibres yellow
Old and larger fibres are red
This can show where tissue remodelling has recently happened
Describe using Masson’s Trichrome as a stain
What it stains/ colour
Nuclei and other basophilic (basic-liking) structures- blue
cytoplasm, muscle, erythrocytes and keratin-bright-red
Collagen is stained -green or blue
Often used to stain connective tissue
Describe using PAS (Periodic Acid Solution) as a stain
What it stains/ colour
Where would you expect to find large glycogen deposits
Carbohydrates and carbohydrate rich macromolecules a deep red colour (magenta)
Nuclei- blue
Glycogen deposits in spleen and liver
What diseases / conditions can be identified using PAS (Periodic Acid Solution) as a stain
If glycogen/neutral polysaccharides are found in basements membranes it could indicate
Gaucher’s disease and Niemann-Pick disease
Demonstrates bile duct basement membrane damage in biliary diseases
Demonstrates the presence of alpha-1 antitrypsin globule
Describe using reticulin as a stain
What it stains/ colour
How
Reticulin fibers -Black
Collagen fibers - Brown
Nuclei -Pink
Reduction of silver ions into silver metal and its deposition on the reticulin fibers to produce a black colour
How can reticulin be used as a strain to study the Liver ?
Reticulin fibers: black Demonstrates the liver architecture
Collagen fibers: brown Demonstrates hepatocyte loss or necrosis
Background: grey to light pink Demonstrates proliferation of hepatocytes (depending on toning)
