Histology: Stains and Cell Ultrastructure Flashcards
Define: Histology
The study of functional tissue
aka Microanatomy
Nomarski (DIC)
pseudo 3D organelles
not used much with tissues
Giemsa Staining
common in research labs
uses eosin and methylene blue to stain cells
What is the most common stain?
Hematoxylin (blue-purple) and Eosin (orange-pink)
(H&E)
Basophilic structures
- Stain with hematoxylin
- ribosomes, nucleic acids, nucleus, rough er
- Basophilic = Blue
Eosinophilic Structures
Acidophilic
stain with Eosin (orange/pink)
mitochondria, lysosomes, cytoplasm
What is normally lost during fixation?
Lipids/Carbohydrates
Ground substance (water, salt)
What are tissues normally processed in?
formaldehyde → it crosslinks proteins
How do you visualize cells in an H&E Stain?
Cytoplasm → pink
nucleus → purple
empty space → where glycogen and other carbohydrates were lost
Cresyl Violet (RNA)
Stains neurons, rough ER, and polysomes really well
Periodic Acid Schiff (PAS)
Stains carbohydrates (basement membrane, mucus) (magenta)
Schiffs reagent stains nuclei (DNA)
counterstain with Fast Green FCF (cytoplasm, collagen)
How does PAS work?
Periodic Acid or its sodium salt oxidizes glycols to aldehydes, which are made visible by exposure to Schiff’s Reagent
What is Schiff’ Reagent made from?
Basic Fuchsine and thionyl chloride
stains nuclei
What is the counterstain for PAS?
Fast Green FCF (stains cytoplasm and collagen)
What does PAS stain?
Carbohydrates (basement membrane, mucus)
Congo Red
Direct cotton dye
hydrogen binding to carbohydrates
elongated hydrophobic structure will bind amyloid fibrils under specific conditions (High pH, rinse with ethanol)
How does Congo Red stain work?
Hydrogen Binding to carbohydrates
Elongated hydrophobic structure will bind amyloid fibrils under specific conditions
What does Congo Red stain?
Amyloid deposits (shown in polarized light (green))
protein carbohydrates
What is a unique feature of Congo Red Stain?
unique feature of amyloid binding: dichroism
Reddish staining in bright-field
Bright Apple Green birefringence under polarized light (glows) → shows amyloid deposits
Where is Congo Red Staining mostly used?
Pathology
Alcian Blue
stains acid mucosubstances
does not usually stain nuclei or RNA
use pink or red counterstain (PAS is compatible)
different pHs stain dif things
What does Alcian Blue stain?
acid mucosubstances
What does Alcian Blue usually NOT stain?
Nuclei or RNA
What happens to a cell with Alcian Blue staining at pH = 2.5?`
all acid mucosubstances stain
What happens to a cell with Alcian Blue staining at pH = 1?`
only sulfated acid mucosubstances will stain
What is a counterstain for Alcian Blue?
pink or red counterstain (PAS is compatible)
What is a counterstain for PAS?
Fast Green FCF
Masson’s Trichrome
stain nuclei with iron-hematoxylin (brownish black)
stains cells and connective tissue different colors
Counterstain with Fast Green FCF (cytoplasm and CT) or aniline blue
and Biebrich Scarlet-Acid Fuchsine (Type I Collagen)
must be careful with fixative used
What does Masson’s Trichrome stain? with what?
Nuclei → Iron-hematoxylin
Cytoplasm and CT → Fast Green FCF or aniline Blue
Type 1 Collagen (Muscle, Cytoplasm, Keratin) → Biebrich Scarlet-Acid Fuchsine
What fixatives work well with Masson’s Trichrome?
Mercury-containing like SUSA
or Zinc-formaline (Kiernan)
What is used as a counterstain for Masson’s Trichrome?
Fast Green FCF (cytoplasm and CT) or aniline Blue
and
Biebrich Scarlet Acid Fuchsine (Type I Collagen)
Which counterstain is the differentiation step in Masson’s Trichrome?
Biebrich Scarlet-Acid Fuchsine
it stains muscle, cytoplasm, and keratin red
Prussian Blue
Reacts chemically to iron present in the tissue and produces an insoluble blue pigment (ferric ferrocyanide)
detects cysteine residues, serotonin, catecholamines, and melanin precursors
What is Prussian Blue made of?
Ferric Ion and ferricyanide
What does Prussian Blue Detect?
detects cysteine residues, serotonin, catecholamines, and melanin precursors
What is Prussian Blue used for pathologically?
to detect iron deposits in tissue
Mucicarmine
Stains Epithelial mucins deep red
Carmine stains nuclei
adds aluminum, changing chemistry
will also stain cryptococcus neoformans (fungus)
What does Mucicarmine stain? what color?
epithelial mucins → deep red
carmine stains nuclei
fungus (Cryptococcus Neoformans)
What is Carmine from Mucicarmine made from?
ground insects
or synthetic alternatives
Verhoeff-van Gieson (VVG)
- Stains elastic fibers
- Two parts:
- Verhoeff’s stain →stains elastic fibers nuclei, and myelin sheaths black
- Van Gieson’s reagent → stains collagen red (Acid fuchsine) and cytoplasm yellow (Picric Acid)
What does VVG stain? what color?
elastic fibers, nuclei, myelin sheaths → black
collagen → red
cytoplasm → yellow
What is VVG made of?
- Verhoeff’s stain → iron hematoxylin + iodine, potassium Iodide
- Van Gieson’s reagent
- Acid Fuchsine (red)
- Picric acid (yellow)