Amyloid and Neuro Stains (Wk 12)

Question 1

Purpose of adding salt to Congo Red staining solutions?

Answer 1

Quenches staining due to ionic charges in tissue - prevents nonspecific staining

Question 2

PAP stain - colour of pre-keratinized (basal) cells and why

Answer 2

Blue-green

Abundant ribosomes

Question 3

Luxol Fast Blue is a large, cationic dye similar to ___________

Answer 3

Alcian Blue

Question 4

This is added to remove some nonspecific staining from connective tissue fibers (like collagen) in Bodian stain

Answer 4

Metallic copper

Question 5

The solution of silver proteinate used in Bodian stain is also known as?

Answer 5

Protaragol

Question 6

Dye that stains keratin in PAP method?

Answer 6

Orange G

Question 7

Bodian - silver is reduced with a developer that contains what 2 reagents

Answer 7

Hydroquinone and formalin

Question 8

Intermediate filament found in axons of neurons

Answer 8

Neurofilament

Question 9

LFB stains myelin through __________ attraction between cationic dye and anionic ________ groups in myelin

Answer 9

electrostatic; phosphate

Question 10

Purpose of sodium hydroxide in Congo Red?

Answer 10

Promotes hydrogen bonds

Question 11

Stain that differentiates between neurons and tumours of neurons (positive) and glial cells and tumours of glial cells (negative)

Answer 11

Neurofilament antibody

Question 12

3 other stains that can demonstrate amyloid and why

Answer 12

Alcian blue
Crystal violet
PAS

Amyloid has high cabohydrate - these are carbohydrate stains

Question 13

Congo Red bonding mechanism and pH

Answer 13

Non-ionic
Likely hydrogen or other weak bonds
Alkaline pH

Question 14

PAP stain - colour of keratinized cells

Answer 14

Pink-orange

Question 15

What tests positive in Lugol’s test?

Answer 15

Positive for starch and amyloid

Question 16

Bodian - what reagent is added to enhance staining of gold?

Answer 16

Oxalic acid

Question 17

Neuro stain that uses ammoniacal silver to impregnate neurons

Answer 17

Bielchowsky’s

Question 18

Luxol Fast Blue - colour of white matter and gray matter

Answer 18

White matter - bright blue

Gray matter - pale blue

Question 19

2 reagents used for differentiation in Luxol Fast Blue

Answer 19

Lithium carbonate, 70% ethanol

Question 20

Difference between plaques and tangles?

Answer 20

Plaques - masses of abnormal proteins (incl. amyloid)

Tangles - clusters of neurofibrils (demonstrated w/ silver stains)

Question 21

What does cresyl violet stain in Luxol Fast Blue?

Answer 21

Nissl and nuclei

Question 22

What does Luxol Fast Blue detect

Answer 22

Myelin

Question 23

What must be avoided due to the weak bonds between dye and tissue in Congo Red?

Answer 23

Excessive dehydration in alcohol

Question 24

3 neurofibril stains

Answer 24

Bodian’s
Bielchowsky’s
Neurofilament antibody

Question 25

Nuclear stain used in PAP method?

Answer 25

Hematoxylin

Question 26

Stain where a solution of silver proteinate (protaragol) impregnates section

Answer 26

Bodian’s

Question 27

In this neuro stain, metallic copper is added to remove some nonspecific staining

Answer 27

Bodian

Question 28

Amyloid has a unique conformation which is known as?

Answer 28

Beta pleated sheet