Fixatives

Question 1

What is the pH range when a formalin pigment may form?

Answer 1

below 6

Question 2

What are the Clarke components?

Answer 2

absolute alcohol and acetic acid

Question 3

What are the Gendre components?

Answer 3

Alcohol saturated with Picric acid, formaldehyde, acetic acid

Question 4

What are the B-5 components?

Answer 4

Mercuric chloride, formaldehyde, sodium acetate

Question 5

What are the Bouin’s components?

Answer 5

Picric acid, formaldehyde, acetic acid

Question 6

What are the Carnoy components?

Answer 6

Chloroform, absolute alcohol, acetic acid

Question 7

What are the Helly Components?

Answer 7

Mercuric chloride, potassium dichromate, formaldehyde

Question 8

What are the Hollande components?

Answer 8

Picric acid, formaldehyde, acetic acid, copper acetate

Question 9

What are the Orth components?

Answer 9

Potassium dichromate, formaldehyde, sodium sulfate.

Question 10

What are the Zamboni components?

Answer 10

Picric acid, paraformaldehyde, phosphate buffer

Question 11

What are the Zenker components?

Answer 11

Mercuric chloride, potassium dichromate, acetic acid

Question 12

What are the fixtives for Urates?

Answer 12

Carnoy or ethanol

Question 13

How to remove Mercury Pigment?

Answer 13

Iodine, then sodium thiosulfate

Question 14

How to remove chrome pigment?

Answer 14

Wash tissue in running water before dehydration

Question 15

How to remove formalin pigment?

Answer 15

absolute alcohol with picrid acid or 70% alcohol containing ammonium hydroxide (aka alkaline alcohol)

Question 16

What is another name for formalin pigment?

Answer 16

Black acid hematin

Question 17

What are uses of Clarke Solution?

Answer 17

Blood smears and frozen sections

Question 18

What is the fixative also used as a mordant in Trichrome stain?

Answer 18

Picric acid

Question 19

What are uses of Methanol as a fixative?

Answer 19

Touch preps and blood smears

Question 20

What fixative is not good for PAS?

Answer 20

gluteraldehyde

Question 21

What fixative is used for pheochromocytomas?

Answer 21

Orth solution

Question 22

What is a secondary fixative used for EM?

Answer 22

Osmium tetroxide

Question 23

What fixatives are not good for silver stains?

Answer 23

Helly, B-5, Zenker

Question 24

What are the non-additive fixatives?

Answer 24

Methanol, ethanol, acetone

Question 25

What is the advantage of Zinc Formalin over Formalin?

Answer 25

Superior nuclear detail

Question 26

What are the actions of acetic acid?

Answer 26

Coag nucleoprotiens, cell swelling, red cell destruction

Question 27

What chemical is used to remove excess picric acid after fixation in Bouin's?

Answer 27

50-70% alcohol

Question 28

What fixative is best for fats?

Answer 28

osmium tetroxide

Question 29

What fixatives are used to fix blood smears?

Answer 29

Clarke or methanol

Question 30

what are the non-aqueous fixatives?

Answer 30

acetone, ethanol, methanol, clarke, carnoy

Question 31

Bouin solution is prepared by combining picric acid with what?

Answer 31

formaldehyde and glacial acetic acid

Question 32

Fixatives containing chromate salts usually require:

Answer 32

washing in water

Question 33

Which of the following fixatives should be used when making a diagnosis of gout?

Answer 33

absolute alcohol

Question 34

Aldehyde fixatives are used for electron microscopy preparations because they:

Answer 34

preserve cell ultrastructure

Question 35

Which would be a good fixative for a silver stain?

Answer 35

glutaraldehyde