SALLY Flashcards
types of tissue/cell morphology?
H&E, papanicolaou, special stains
IHC & ICC
light microscopy and EM
ENDoscopy?
anywhere
SIGMOIDoscopy?
colon
COLPoscopy?
cervix
BRONCHoscopy?
lungs
LARYNGoscopy?
larynx
GASTRoscopy?
stomach
ARTHRoscopy?
joints
CYSToscopy?
bladder
types of biopsies?
needle, shave and punch
cytology sampling methods:
fluids contains exfoliated cells
scrapes
impressions
brushings
washings / lavage
needle aspiration
where can you collect samples from?
reproductive, urinary, respiratory, and GI tract
body cavities, thyroid, skin, breast, lymph nodes, and bone marrow
advantages of cytology?
low cost
low risk
accessibility
rapid
avoids hospitalisation
disadvantages of cytology?
subjective
inaccurate in the wrong hands
might not tell you tumour origin, type, grade, stage
might not distinguish invasive vs pre-invasive disease
preparation for cytology samples:
direct smearing onto slide
cytocentrifugation onto slide
cell blocks
fixation
LBC
what does fixation do?
prevents cells from degenerating and maintains tissue morphology
examples of fixatives?
formaldehyde, alcohol, chromic acid
when would decalcification occur?
when dealing with bone samples, removes calcium, doesn’t affect staining
what does processing a sample involve?
dehydration, clearing and impregnation
last 3 steps to prepare samples are?
embedding, sectioning and freezing
vital stain?
tryphan blue
What are the types of light microscopy?
Bright field, Dark field, Phase contrast, Polarized light
Polarized light is used for crystal structures.
What is the primary method of visualization in microscopy?
Staining
Unstained tissues are difficult to see.
Name three natural dyes used in staining.
- Saffron (crocus)
- Cochineal
- Hematoxylin (from wood of Haematoxylum campechianum)
What are the two main staining methods?
- Staining with dyes
- Impregnation with metallic salts
- Formation of colored compounds by means of chemical reactions
What is the role of chromophore in dyes?
Confers color to the dye.
What is the role of auxochrome in dyes?
Confers charge to the dye.
What is H&E staining?
A staining method using Hematoxylin and Eosin.
What color does Hematoxylin stain nuclei?
Blue / purple.
What color does Eosin stain cytoplasm and connective tissue?
Varying shades of pink / red.
What is the function of a mordant in staining?
Helps Hematein bind to tissues.
Optimal pH for eosin?
pH of 4.5-5.0 for optimal binding.
What is metachromasia?
a disorder when certain stains cause cells and tissues to change color significantly from the stain’s original color
Metachromatic dyes change color when added to tissues without changing chemical structure.
Give an example of a metachromatic dye.
- Methylene blue
- Methyl violet
- Toluidine blue
What is the Argyophil reaction?
reduces AgNO3 to metallic silver
requires a reducing agent
What is the Argentaffin reaction?
Does not require a reducing agent.
used in impregnation with metallic salts
What is an example of a chemical reaction in staining?
direct reaction between solution and tissue to give coloured product / intermediate
e.g. Perl’s reaction for hemosiderin, PAS, HRP & DAB
What does immunocytochemistry demonstrate?
Antigens in tissues or smears using specific antibody-antigen interactions.
What does the ABP amplification of signal stand for?
A = avidin, B = biotin, P = peroxidase.
What is antigen retrieval?
Process to remove cross-links that affect antibody binding.
What early method was used for restoration of staining?
Acid as formalin as fixative.
What are some considerations for optimizing staining protocols?
- Buffer type and volume
- Time of treatment
- Number of slides
- Cooling time
