PAGE 8

Question 1

Picric acid (Bouin’s solution)

Answer 1

50 - 70% ALCOHOL

Question 2

Mercuric fixatives

Answer 2

ALCOHOLIC IODIDE

Question 3

FIXATIVES FOR WASHING-OUT: REMOVAL OF PIGMENT AFTER FIXATION

Answer 3

1. FORMALIN
2. PICRIC ACID
3. MERCURIC FIXATIVE
4. MELANIN
5. OTHERS

Question 4

WASHING OUT USING FORMALIN

Answer 4

➢ (white ppt): filtration; + 10% methanol
➢ brown/black: Alkaline Picrate (Picric acid + 95% EA)
: 1% KOH in 80% alcohol
➢ Kardasewitsch’s: 28%NH3 H2O + 70% EA
➢ Lillie’s: 28%NH3 H2O, acetone + H2O2 (wash in 70% Alcohol)

Question 5

WASHING OUT USING PICCRIC ACID

Answer 5

➢ Sat. Li2CO3 in 70 % EA
➢ 70% EA then 5% Na thiosulfate
➢ Lenoir’s solution: conc. NH4Ac, 95% EA & dist. H2O

Question 6

WASHING OUT USING MERCURIC FIXATIVE

Answer 6

➢ 0.5% Iodine solution in 70% ethanol (5-10 mins
➢ Decolorizer: 5% Na thiosulfate
➢ Langeron’s iodine: I2 crystals, KI, Dist H2O

Question 7

WASHING OUT USING MELANINE

Answer 7

➢ KMnO4 (decolorize)
➢ Pyrogallic acid (reduce)
➢ H2O2 (bleach & final removal)

Question 8

WASHING OUT USING CARNOY’S

Answer 8

100% ALCOHOL

Question 9

FIXATION FOR ELECTRON MICROSCOPY

Answer 9

1. ALDEHYDE FIXATION

2. OSMIC ACID FIXATION

Question 10

preserve cellular structure & require short fixation time

Answer 10

FIXATIVES

Question 11

ALDEHYDE FIXATION FOR ELECTRON MICROSCOPY

Answer 11

1. KARNOVSKY’S PARAFORMALDEHYDE-GLUARALDEHYDE

2. ACROLEIN

Question 12

OSMIC ACID FIXATION

Answer 12

1. Palade’s fixative
2. Zetterqvist Osmium fixative
3. Millonig’s Osmium tetroxide

Question 13

FIXATIVES FOR ENZYME HISTOCHEMISTRY

Answer 13

1. 4% formaldehyde or formol-saline

2. Frozen sections: acetone or formaldehyde