7.1 STAINING INTRO,A-B

Question 1

What are the three main types of simple carbohydrates and examples of each?

Answer 1

Monosaccharides (glucose

Question 2

What are glycoconjugates?

Answer 2

Molecules composed of carbohydrates linked to other substances

Question 3

What are the main categories of glycoconjugates?

Answer 3

Connective tissue glycoconjugates; mucins; other glycoproteins; glycolipids

Question 4

What are the connective tissue glycoconjugates?

Answer 4

Proteoglycans and hyaluronic acid

Question 5

What are mucins?

Answer 5

Neutral mucins; sialomucins; sulfomucins

Question 6

What are examples of other glycoproteins?

Answer 6

Membrane proteins; blood group antigens

Question 7

What are glycolipids?

Answer 7

Cerebrosides; gangliosides

Question 8

Which glycosaminoglycan is most abundant?

Answer 8

Chondroitin sulfate

Question 9

Where is chondroitin sulfate found?

Answer 9

Cartilage; tendons; ligaments; aorta; cell membranes

Question 10

Which fixatives are superior for carbohydrate staining?

Answer 10

Alcoholic formalin (including Rossman’s fluid)

Question 11

Which fixative is acceptable but less ideal for carbohydrate staining?

Answer 11

Neutral buffered formalin

Question 12

Which fixatives are not advised for carbohydrate staining?

Answer 12

Mercuric chloride-containing fixatives (Zenker’s acetic acid; Susa)

Question 13

What is the principle of the Periodic Acid Schiff (PAS) reaction?

Answer 13

Periodic acid oxidizes 1

Question 14

Which carbohydrates and tissue components are PAS-reactive?

Answer 14

Glycogen; starch; mucins (sialomucin; neutral mucin); basement membranes; α-antitrypsin; reticulin; fungi capsules; pancreatic zymogen granules; thyroid colloid; corpora amylacea; Russell bodies

Question 15

What is the purpose of PAS with diastase method?

Answer 15

To distinguish glycogen from mucins by digesting glycogen with diastase

Question 16

What is the Best Carmine method used for?

Answer 16

Staining glycogen

Question 17

What is the staining characteristic of Best Carmine?

Answer 17

Alkaline carminic acid stains glycogen bright red; Ehrlich’s hematoxylin counterstains nuclei blue

Question 18

What are acid mucopolysaccharides?

Answer 18

Polysaccharides with hexuronic acid bound to sulfuric acid esters and proteins

Question 19

What are examples of acid mucopolysaccharides?

Answer 19

Hyaluronic acid; heparan sulfate; chondroitin sulfate

Question 20

Which staining techniques are used for acid mucopolysaccharides?

Answer 20

Metachromatic staining (toluidine blue; Azure A); Alcian blue; colloidal iron; aldehyde fuchsin; mucicarmine; fluorescent acridine orange

Question 21

What is the staining result of Alcian blue for acid mucins?

Answer 21

Acid mucins stain blue; nuclei stain red

Question 22

How does the combined Alcian blue-PAS-hematoxylin technique differentiate mucins?

Answer 22

Acid mucins stain blue (Alcian blue); neutral mucins stain magenta (PAS); nuclei stain pale blue

Question 23

What is the specificity of mucicarmine stain?

Answer 23

Specific for mucin of epithelial origin

Question 24

What is the staining result of mucicarmine?

Answer 24

Mucins stain red; nuclei blue; background unstained

Question 25

What is the principle of the colloidal iron technique?

Answer 25

Adsorption of colloidal iron at low pH onto acid mucins

Question 26

What are neutral mucopolysaccharides?

Answer 26

Polysaccharides found in glands of the GI tract (esophagus; stomach) and prostate

Question 27

How do neutral mucopolysaccharides stain?

Answer 27

Stain red with PAS; do not stain with Alcian blue; colloidal iron; mucicarmine; or metachromatic dyes

Question 28

What are simple lipids?

Answer 28

Esters of fatty acids with alcohols

Question 29

What is the main function of simple lipids?

Answer 29

Energy stores in adipose tissue

Question 30

What are triglycerides composed of?

Answer 30

Esters of fatty acids with glycerol

Question 31

How are triglycerides stained?

Answer 31

Sudan Black B; Sudan IV; Oil Red O

Question 32

What are compound lipids?

Answer 32

Lipids consisting of fatty acid; alcohol; and additional groups such as phosphorus or nitrogen

Question 33

What are the main types of compound lipids?

Answer 33

Phospholipids; glycolipids

Question 34

Where are phospholipids mainly found?

Answer 34

Cellular membranes

Question 35

How are phospholipids stained?

Answer 35

Sudan Black B; acid hematin

Question 36

What are glycolipids composed of?

Answer 36

Fatty acids and hexoses

Question 37

How are glycolipids stained?

Answer 37

Sudan Black B; PAS techniques

Question 38

What are derived lipids?

Answer 38

Fatty acids derived from hydrolysis of simple and compound lipids

Question 39

What are examples of derived lipids?

Answer 39

Cholesterol; bile acids; sex hormones; adrenocortical hormones

Question 40

Why is adipose tissue difficult to demonstrate histologically?

Answer 40

Lipids dissolve in solvents used for paraffin processing

Question 41

What is the best method to demonstrate adipose tissue?

Answer 41

Cryostat sections of fresh unfixed tissue

Question 42

What are lipochrome (lipofuscin) pigments?

Answer 42

Breakdown products from oxidation of lipids and lipoproteins

Question 43

Where are lipochrome pigments found?

Answer 43

Heart; liver; CNS; adrenal cortex

Question 44

What are the staining characteristics of lipochrome pigments?

Answer 44

PAS positive; variably acid fast; stain with Ziehl-Neelsen; Sudan Black B and Sudan Red positive

Question 45

What is Sudanophilia?

Answer 45

The property of tissues to be stained with fat or oil-soluble dyes due to their lipid nature

Question 46

Which Sudan dyes are basic aryl amines with low water solubility?

Answer 46

Sudan Black B; Sudan Red VII B

Question 47

Which Sudan dyes belong to B-Naphthols?

Answer 47

Sudan III (orange-red); Sudan IV (Scharlach B; red)

Question 48

What is the Sudan Black B method used for?

Answer 48

Most sensitive lipid stain

Question 49

What does Sudan Black B stain?

Answer 49

Phospholipids and neutral fats blue-black; nuclei stain red

Question 50

What is the staining result of Sudan IV (Scharlach R) stain?

Answer 50

Lipids (mainly triglycerides) stain red; nuclei stain blue/black

Question 51

What is the principle of Oil Red O staining?

Answer 51

Oil-soluble dye with increased solubility in fatty substances

Question 52

What does Oil Red O stain?

Answer 52

Neutral fats and lipofuscin bright red; nuclei stain blue

Question 53

What is the function of osmium tetroxide (osmic acid) in fat staining?

Answer 53

Not a dye but an unstable oxide reduced to a permanent black precipitate staining fats black