STAINING Flashcards
dye that are obtained from plants and animals
natural dyes
natural dye example
hematoxylin
hematoxylin tree source
heartwood (Haematoxylum campechianum)
active coloring substance of the hematoxylin, ripened/oxidized
hematein
what is needed to stain tissues with hematein?
mordant
stain + mordant + tissues =
dye lake
dye extracted from female cochineal bug (Coccus cacti)
cochineal dye
cochineal dye + alum
carmine stain (chromatin stain)
used for neuropathological studies
picrocarmine (carmine + picric acid)
used for demonstration of mucins and Cryptococcus neoformans
mucicarmine (carmine + alum hydroxide)
used for demonstration of glycogen
best’s carmine (carmine + aluminum chloride)
also known as coal tar dyes, derived from benzene
synthetic dyes
synthetic dyes are collectively known as
aniline dyes
benzene + chromphore
chromogen (temporary until auxochrome)
chromogen + auxochrome
dye
function of auxochrome
responsible for dyeing property
function of chromophore
responsible for coloring property
dye modifier groups:
ethyl groups
methyl groups
sulphonic groups
chromophore groups:
quinoid ring
azo groups
xanthene
quinone-imine group
auxochrome groups:
cationic auxochrome: amino
anionic auxochrome: hydroxyl and carboxyl
dye to tissue mechanisms:
majority of tissue-dye reactions
electrostatic
stains that use electrostatic:
neutral red
light green
stains that use hydrogen bonding:
congo red, carmine, weigert-type resorcinol dye
gold standard for amyloid demonstration
congo red
stains that use van der waals forces:
alum hematoxylin solutions
stains that use physical staining:
sudan dyes
property of tissues to be stained with fat or oil-soluble dyes, regardless of the type of dye used, due to their essential lipid nature
sudanophilia
stains that use natural affinity:
janus green
methods of staining:
accdg to presence of mordant
gives color to the sections by using simple aqueous or alcoholic dye solutions
direct staining
direct staining example:
methylene blue
methods of staining:
accdg to presence of mordant
action of dye is intensified by using mordant
indirect staining