Staining Flashcards
(16 cards)
What is the use of H and E stain
used to visualise microscopic structure of tissues and cells
How many components does it have
2
Heamtoxylin and Eosin
What does haemotoxylin stain
Nucleus and other acidic structures like DNA or RNA
Stains them blue/purple
What does eosin stain
It’s a negatively charged acidic dye
Stains cytoplasmic components and ECM such as collagen and connective tissues.
Stains them pink or red
What does overstaining and differentiation mean
Overstaining: If too much stain is applied, the tissue may become overly dark, making it difficult to distinguish cellular components.
Differentiation: This is a process that involves using solutions to wash out excess stains, ensuring that the tissue is stained appropriately. It helps to achieve the correct balance between Hematoxylin (nuclear staining) and Eosin (cytoplasmic and extracellular staining), which is crucial for accurate diagnosis.
What is the use of Periodic acid Schiff stain (PAS)
highlights the presence of carbodydrates like glycogen, glycoproteins and proteoglycans within tissue and cells
What does periodic stain do?
It’s a strong oxidising agent.
Selectively oxidises the diol (thwo hydroxyl groups) functional groups present in carbohydrates
What does Schiffs Reagent do
After the tissue is treated with periodic acid, it is then treated with Schiff’s reagent.
It reacts with aldehydes produced by periodic acid oxidation
This reaction results in the formation of a magenta or pink colour where carbohydrates
are present.
What other counterstain is used in PAS
To help you see the cell nuclei (the center of the cells where DNA lives), another dye is added after PAS. This is called a counterstain.
The most common counterstain is hematoxylin, which turns the nuclei blue or purple.
So, when you look under a microscope:
Sugary parts = pink
Nuclei = blue or purple
What is Haemotoxylin and Van Gieson’s stain
Used simultaneously for different purposes.
HA- used to stain nuclei blur or purple
What is Van Gieson’s stain used for
It’s a combination of piric acid and fuchsin
Priric stains collagen fibres yellow
Fuchsin stains elastic fibres and muscles fibres red
How do u carry out dehydration
By putting them through increasing strengths of alcohol
Is rehydration or dehydration carried out first
Rehydration - to remove wax
Then dehydration
Why are coverslips needed
Protection, Tissue preservation, optical clarity, minisimg evaporation, improved handling, dust and contamination protection
What is Perls Prussian Blue stain used for
To detect iron in tissues, especially stored iron like hemosiderin.
Formation of blue colour
What is Gordons and Sweets stain used for
To see rectangular fibres
Turns them black
