PICRIC ACID AND ALCOHOL FIXATIVES

Question 1

Normally used in strong aqueous solution (1%)
Glycogen demonstration
Highly explosive when dry
• Remedy: add distilled H20 or 0.5% - 1% saturated alcohol

Answer 1

PICRIC ACID FIXATIVES

Question 2

Picric acid

Highly explosive when dry
• Remedy:

Answer 2

add distilled H20 or 0.5% - 1% saturated alcohol

Question 3

PICRIC ACID

• Yellowing effect
• Remedy:

Answer 3

immerse in Li2CO3 with 70%ROH → water → 70% ethanol → 5%
Na thiosulfate → water

Question 4

• For embryo and pituitary biopsies, and tissues to be stained with Masson’s Trichrome

Answer 4

Bouin’s

Question 5

Advantage: minimum cell shrinkage and tissue hardening due to counter=balance effect of glacial HAc (swelling) and picric acid (shrinking)

Disadvantage: poorly penetrates large tissue, thus limited to small fragments of tissues

Answer 5

Bouin’s

Question 6

• Better and less messy than Bouin’s

Answer 6

Brasil’s Alcoholic Picroformol

Question 7

• Incorporated in compound fixatives

• Important for nuclear fixatives (precipitates nucleoproteins, chromatins)

• Destroys mitochondria and Golgi elements, thus not for cytoplasmic fixation

Answer 7

Glacial Acetic Acid

Question 8

Glacial Acetic Acid

• Solidifies at

Answer 8

17°C

Question 9

Advantage: good for glycogen

Answer 9

Alcohol Fixatives

Question 10

Disadvantage: dissolves Fats and Lipoproteins

Answer 10

Alcohol FIxatives

Question 11

Effect: rapidly denatures and precips CHONs, preserves nuclear stains

Answer 11

Alcohol fixatives

Question 12

Most rapid tissue fixative (____)

Fixing brain tissues for rabies diagnosis

Fixes Niss granules and cytoplasmic granules

Answer 12

Carnoy’s Fluid 1-3 hrs

Question 13

Enzyme studies; does not fix but preserves glycogen

Answer 13

Ethanol (70 - 100%)

Question 14

Dry and wet smears, Bone Marrow smears, bacterial smears

Answer 14

Methanol / Wood Alcohol (100%)

Question 15

Touch prep smears to be Wright-stained

Answer 15

Isopropanol

Question 16

For mucopolysaccharide (_____)

Answer 16

Newcomer’s Fluid

12-18 hrs

Question 17

• For sputum (______)

Answer 17

Gendre’s (Alcoholic Formalin)

4 - 18hrs