Topic 2 (histology) Flashcards
(30 cards)
When confirming responses to drugs, post op treatment is called what?
Adjuvant
When confirming responses to drugs, pre op treatment is called what?
Neoadjuvant
What are the first 5 steps of histology
Obtaining tissue Fixation Cutting Tissue processing Section cutting / mounting
What are the final 5 steps of histology
Section staining Section scanning Microscopy Diagnosis Prognosis
Why does fixing need to be done fast?
Tissue starts to dehydrate fast
Purpose of fixation other than dehydration (3)
Stops intrinsic autolysis
Prevents putrefaction
Increases mechanical strength
How does formalin work?
Forms protein covalent cross links
Whats formalin good for?
What formalin bad for?
Good tissue morphology
Poor DNA / RNA preservation
What does glutaraldehyde used for?
What does it need (2)
EM
Needs small samples / low temperature
What does freezing do (bad)
Poor morphology but fast
For cytology smears, what fixative is used?
Ethanol
Once cutting is done, where is it placed into?
A cassette
List the processing of tissue processing
Dehydration
Clearing
Wax infiltration
Embedding
How is the dehydration stage done in tissue processing?
Adding of alcohol
removes water
What is used to remove alcohol from tissue processing
Xylene
What is used to remove xylene for wax infiltration
Paraffin wax
With the embedding stage, what is finally formed?
Formalin Fixed Paraffin Embedded Tissue (FFPET)
What is used in section cutting/mounting
Microtomy
How does Haematoxylin work?
Stains Acidic (DNA/Nuclei) purple
How does Eosin work?
Stains Basic (structures) pink
What does PAS detect?
Mucins + BM + Fungal organisms
If gram stain goes blue, what bacteria?
Positive bacteria
Giemsa stain looks for what?
H.pylori
Grocotts stain stains what?
Fungi walls
