Fixation
The primary purpose of fixation is to:
a. stop enzymatic action
b. remove the water from the tissue
c. provide support for the tissue
d. autolyze the tissue - answera. stop enzymatic action
Which of the following fixatives contains picric acid, formalin, and acetic acid?
a. Zenker
b. Helly
c. Bouin
d. Zamboni - answerc. Bouin
The volume of a fixative should exceed the volume of the tissue by:
a. 1x to 2x
b. 5x to 10x
c. 15x to 20x
d. 25x to 50x - answerc. 15x to 20x
Tissue must be washed in running water after fixation in:
a. Zenker solution
b. absolute alcohol
c. glyoxal
d. formalin - answera. Zenker solution
Which of the following contains formalin, potassium dichromate, and mercuric chloride?
a. Zenker
b. Helly
c. Carnoy
d. Orth - answerb. Helly
Precipitate left in tissues that have been fixed in solutions containing mercuric chloride
may be removed by immersion in:
a. running water
b. sodium thiosulfate
c. weak ammonia water
,d. iodine - answerd. iodine
Commercial stock formaldehyde solutions contain:
a. 4% formaldehyde
b. 10% formaldehyde
c. 37-40% formaldehyde
d. 98-100% formaldehyde - answerc. 37-40% formaldehyde
Formalin pigment would almost certainly be formed when the pH of the formalin is:
a. 5
b. 6
c. 7
d. 8 - answera. 5
Formalin pigment may be removed from tissue by:
a. running water
b. alcoholic iodine
c. alcoholic picric acid
d. potassium permanganate - answerc. alcoholic picric acid
10% formalin is the same as:
a. 37-40% formaldehyde
b. 10% formaldehyde
c. 4% formaldehyde
d. 1% formaldehyde - answerc. 4% formaldehyde
For best results when using formalin as a routine fixative, it must be made:
a. acidic
b. basic
c. neutral
d. isoelectric - answerc. neutral
Absolute alcohol is indicated as a primary fixative if the tissue is to be processed for the
demonstration of:
a. fat
b. immunofluorescence
c. enzymes
d. urate crystals - answerd. urate crystals
Putrefaction of tissue is caused by:
, a. enzymatic activity
b. bacterial action
c. aqueous fixatives
d. overfixation - answerb. bacterial action
To prepare 10% solution of formalin, which of the following amounts of water should be
added to 100 mL of stock formaldehyde?
a. 1000 mL
b. 900 mL
c. 450 mL
d. 10 mL - answerb. 900 mL
The ratio of stock solution to acid in Zenker fixative is:
a. 95 parts stock to 5 parts hydrochloric acid
b. 95 parts stock to 5 parts acetic acid
c. 95 parts stock to 5 parts formaldehyde
d. 99 parts stock to 1 part acetic acid - answerb. 95 parts stock to 5 parts acetic acid
Which of the following tissue changes will occur if acetic acid is used alone as a
fixative?
a. swelling
b. shrinkage
c. overhardening
d. poor nucleoprotein preservation - answera. swelling
A good fixative for central nervous system tissue to be stained with silver or gold
techniques is:
a. Zenker solution
b. neutral buffered formalin
c. Bouin solution
d. formalin ammonium bromide - answerd. formalin ammonium bromide
After fixing tissue in Bouin solution, the excess picric acid is frequently removed by
washing in:
a. running water
b. absolute alcohol
c. 50-70% alcohol
d. phosphate buffer - answerc. 50-70% alcohol
Carnoy fluid is prepared with acetic acid, alcohol, and:
The primary purpose of fixation is to:
a. stop enzymatic action
b. remove the water from the tissue
c. provide support for the tissue
d. autolyze the tissue - answera. stop enzymatic action
Which of the following fixatives contains picric acid, formalin, and acetic acid?
a. Zenker
b. Helly
c. Bouin
d. Zamboni - answerc. Bouin
The volume of a fixative should exceed the volume of the tissue by:
a. 1x to 2x
b. 5x to 10x
c. 15x to 20x
d. 25x to 50x - answerc. 15x to 20x
Tissue must be washed in running water after fixation in:
a. Zenker solution
b. absolute alcohol
c. glyoxal
d. formalin - answera. Zenker solution
Which of the following contains formalin, potassium dichromate, and mercuric chloride?
a. Zenker
b. Helly
c. Carnoy
d. Orth - answerb. Helly
Precipitate left in tissues that have been fixed in solutions containing mercuric chloride
may be removed by immersion in:
a. running water
b. sodium thiosulfate
c. weak ammonia water
,d. iodine - answerd. iodine
Commercial stock formaldehyde solutions contain:
a. 4% formaldehyde
b. 10% formaldehyde
c. 37-40% formaldehyde
d. 98-100% formaldehyde - answerc. 37-40% formaldehyde
Formalin pigment would almost certainly be formed when the pH of the formalin is:
a. 5
b. 6
c. 7
d. 8 - answera. 5
Formalin pigment may be removed from tissue by:
a. running water
b. alcoholic iodine
c. alcoholic picric acid
d. potassium permanganate - answerc. alcoholic picric acid
10% formalin is the same as:
a. 37-40% formaldehyde
b. 10% formaldehyde
c. 4% formaldehyde
d. 1% formaldehyde - answerc. 4% formaldehyde
For best results when using formalin as a routine fixative, it must be made:
a. acidic
b. basic
c. neutral
d. isoelectric - answerc. neutral
Absolute alcohol is indicated as a primary fixative if the tissue is to be processed for the
demonstration of:
a. fat
b. immunofluorescence
c. enzymes
d. urate crystals - answerd. urate crystals
Putrefaction of tissue is caused by:
, a. enzymatic activity
b. bacterial action
c. aqueous fixatives
d. overfixation - answerb. bacterial action
To prepare 10% solution of formalin, which of the following amounts of water should be
added to 100 mL of stock formaldehyde?
a. 1000 mL
b. 900 mL
c. 450 mL
d. 10 mL - answerb. 900 mL
The ratio of stock solution to acid in Zenker fixative is:
a. 95 parts stock to 5 parts hydrochloric acid
b. 95 parts stock to 5 parts acetic acid
c. 95 parts stock to 5 parts formaldehyde
d. 99 parts stock to 1 part acetic acid - answerb. 95 parts stock to 5 parts acetic acid
Which of the following tissue changes will occur if acetic acid is used alone as a
fixative?
a. swelling
b. shrinkage
c. overhardening
d. poor nucleoprotein preservation - answera. swelling
A good fixative for central nervous system tissue to be stained with silver or gold
techniques is:
a. Zenker solution
b. neutral buffered formalin
c. Bouin solution
d. formalin ammonium bromide - answerd. formalin ammonium bromide
After fixing tissue in Bouin solution, the excess picric acid is frequently removed by
washing in:
a. running water
b. absolute alcohol
c. 50-70% alcohol
d. phosphate buffer - answerc. 50-70% alcohol
Carnoy fluid is prepared with acetic acid, alcohol, and:
