intro Flashcards
how can sections of tissue be obtained?
formalin fixed or frozen tissues
Normally 4-10% neutral buffered formalin is used and tissues are soaked in__ times their volume for a minimum of __ hours
10
48
what happens to tissue prior to embedding?
transferred to 50-70% ethanol
how are frozen tissues embedded?
OCT compound and kept frozen
how are formalin tissues embedded?
placed in cassette and embedded in paraffin or resin
why is embedding required?
to make blocks of the tissues that can be stored for a long time and sectioned when needed
The harder the embedding medium, _______ the section
thinner
what does hematoxylin stain and what color does it appear?
nucleic acids, nuclei of cells and ribosomes of cytoplasm
blue
what does the eosin stain and what color appears?
proteins
stains cytoplasm and extracellular matrix pink
what is used to visualize connective tissue and increase contrast?
masson’s trichrome
what colors does masson’s trichrome stain
connective tissue = blue
muscle = red
what is periodic-acid schiff (PAS) used to stain?
polysaccharides and fungi
what is gram’a stain used for?
bacteria
what is congo red used to stain for?
amyloid
what is susan/oil red O used to stain for?
lipids- effective when used on frozen sections
