Amyloid and Neuro Stains (Wk 12) Flashcards
Purpose of adding salt to Congo Red staining solutions?
Quenches staining due to ionic charges in tissue - prevents nonspecific staining
PAP stain - colour of pre-keratinized (basal) cells and why
Blue-green
Abundant ribosomes
Luxol Fast Blue is a large, cationic dye similar to ___________
Alcian Blue
This is added to remove some nonspecific staining from connective tissue fibers (like collagen) in Bodian stain
Metallic copper
The solution of silver proteinate used in Bodian stain is also known as?
Protaragol
Dye that stains keratin in PAP method?
Orange G
Bodian - silver is reduced with a developer that contains what 2 reagents
Hydroquinone and formalin
Intermediate filament found in axons of neurons
Neurofilament
LFB stains myelin through __________ attraction between cationic dye and anionic ________ groups in myelin
electrostatic; phosphate
Purpose of sodium hydroxide in Congo Red?
Promotes hydrogen bonds
Stain that differentiates between neurons and tumours of neurons (positive) and glial cells and tumours of glial cells (negative)
Neurofilament antibody
3 other stains that can demonstrate amyloid and why
Alcian blue
Crystal violet
PAS
Amyloid has high cabohydrate - these are carbohydrate stains
Congo Red bonding mechanism and pH
Non-ionic
Likely hydrogen or other weak bonds
Alkaline pH
PAP stain - colour of keratinized cells
Pink-orange
What tests positive in Lugol’s test?
Positive for starch and amyloid
Bodian - what reagent is added to enhance staining of gold?
Oxalic acid
Neuro stain that uses ammoniacal silver to impregnate neurons
Bielchowsky’s
Luxol Fast Blue - colour of white matter and gray matter
White matter - bright blue
Gray matter - pale blue
2 reagents used for differentiation in Luxol Fast Blue
Lithium carbonate, 70% ethanol
Difference between plaques and tangles?
Plaques - masses of abnormal proteins (incl. amyloid)
Tangles - clusters of neurofibrils (demonstrated w/ silver stains)
What does cresyl violet stain in Luxol Fast Blue?
Nissl and nuclei
What does Luxol Fast Blue detect
Myelin
What must be avoided due to the weak bonds between dye and tissue in Congo Red?
Excessive dehydration in alcohol
3 neurofibril stains
Bodian’s
Bielchowsky’s
Neurofilament antibody
Nuclear stain used in PAP method?
Hematoxylin
Stain where a solution of silver proteinate (protaragol) impregnates section
Bodian’s
In this neuro stain, metallic copper is added to remove some nonspecific staining
Bodian
Amyloid has a unique conformation which is known as?
Beta pleated sheet
