Microscopy Flashcards
Define tissue
A collection of cells specialised to perform a particular function e.g. Epithelia
State the hierarchy of measurement units
M,mm,um,no
Explain the value of histology in diagnosis
Can give certainty, biopsy is proof
Define biopsy
removal of small piece of tissue
What is curettage used for?
Endometrial lining of uterus
What is smear used for?
Cervix,Buccal
What is needle used to sample?
Brain, breast, liver
What is direct incision used to sample?
Skin, mouth, larynx
What is endoscopic used for?
Lung, intestine, bladder
What is transvascular used to sample?
Heart and liver
Why is tissue fixed?
Macromolecules cross linked
Preserve cellular structure
No auto lysis or putrefaction
List common fixatives
Gluteraldehyde
Formaldehyde
Dehydrated with ethanol, cleared with toluene, wax
How do shrinkage artefacts occur?
During slide preparation dehydration and rehydration leads to abnormalities
How does h and e stain work?
Haemotoxin stains acidic components purple e.g. DNA RNA
Eosin stains basic components pink e.g. Proteins, fibres
How does periodic acid shift stain?
Stains glycoproteins magenta
What is phase contrast and its advantages?
Used inteferance effects from two combining light waves
Can enhance image of Unstained cells
What is dark field and its advantages?
Excludes The U scattered beam from the image
Can use on Unstained, detects syphyllis and malaria
What is flourescent and its advantages?
Targets molecules of interest with flourescent ab
Can use multiple stains on one sample
What is confocal and its advantages?
Tissue labelled with one or more fluorescent particles
Eliminates flare, 3d from 2d, living specimens
