STOOL FIXATIVES AND CELLOPHANE TAPE METHOD

Question 1

7 fixatives

Answer 1

● Formalin
● Merthiolate-iodine-formalin (MIF)
● Polyvinyl Alcohol (PVA)
● Sodium acetate-acetic acid-formalin (SAF)
● Schaudinn’s Fixative
● Modified PolyvinylAlcohol (Modified PVA)
● One-vial Fixatives

Question 2

______________ formalin are commonly used

Answer 2

5% and 10%

Question 3

5% of formalin are ___________

Answer 3

protozoan cysts (not including trophozoites)

Question 4

10% of formalin are _____________

Answer 4

helminth eggs and larva

Question 5

describe formalin

Answer 5

5PLEA
● 5% and 10% formalin are commonly used
● preserves specimens up to several years
long shelf-life
● easy to prepare
● all-purpose fixative

Question 6

______ and ____________ are staining components

Answer 6

Merthiolate and iodine

Question 7

preservative (actual fixative

Answer 7

formalin

Question 7

____________ is also known as thimerosal

Answer 7

Merthiolate

Question 8

Main purpose: melthiolate-iodine formalin

Answer 8

fixation of intestinal protozoans, helminth
eggs and larvae

Question 9

There is a possibility that you will encounter difficulty in the
specific identification of protozoans

Answer 9

B. MERTHIOLATE-IODINE-FORMALIN (MIF)

Question 10

A plastic powder that can act as an adhesive for the stool
specimen when preparing slides for staining

Answer 10

C. POLYVINYL ALCOHOL (PVA)

Question 11

● Has good adhesive property

Answer 11

C. POLYVINYL ALCOHOL (PVA)

Question 12

Suitable for permanent smears that are stained with
trichrome

Answer 12

C. POLYVINYL ALCOHOL (PVA)

Question 13

good in preserving protozoan trophozoites and cysts
○ But not good for helminth eggs, larvae, poxidia,
and microsporidia

HLPM

Answer 13

C. POLYVINYL ALCOHOL (PVA)

Question 14

used in preparation of permanent stained smear

Answer 14

C. POLYVINYL ALCOHOL (PVA)

Question 15

● long shelf life when stored at RT

Answer 15

C. POLYVINYL ALCOHOL (PVA)

Question 16

● concentration technique can be performed with
PVA-preserved specimen but not as effective as formalin

Answer 16

C. POLYVINYL ALCOHOL (PVA)

Question 17

two vial system in laboratories

Answer 17

one portion for the stool specimen and other for the polyvinyl alcohol (PVA)

Question 18

similar to PVA as to what it preserves, what is suitable or not when used
and having mercuric chloride as one of its component

Answer 18

SCHAUDINN’S FIXATIVE

Question 19

 poor adhesion of liquid or mucoid specimens to slides

Answer 19

SCHAUDINN’S FIXATIVE

Question 20

● used for performing concentration techniques and
permanent stained smears
● long shelf-life
● easy to prepare
● mercury-free

Answer 20

Sodium acetate acetic acid formalin

Question 21

Sodium acetate- acetic acid formalin is suitable for

Answer 21

Acid fast stain
○ Safranin
○ Chromotrope stain

Question 22

Allow the additive to be spread on the slide before
putting the specimen

Answer 22

SODIUM ACETATE-ACETIC ACID FORMALIN (SAF)

Question 23

● Another alternative for mercury based fixative (no mercury)
● similar to SAF wherein it can be used for concentration
methods and permanent stained smears
● uses a substitute compound (zinc sulfate or copper sulfate

Answer 23

F. MODIFIED POLYVINYL ALCOHOL

Question 24

similar to SAF wherein it can be used for concentration
methods and permanent stained smears

Answer 24

F. MODIFIED POLYVINYL ALCOHOL

Question 25

uses a substitute compound (zinc sulfate or copper sulfate)

Answer 25

MODIFIED POLYVINYL ALCOHOL

Question 26

PVA gives more better results

Answer 26

F. MODIFIED POLYVINYL ALCOHOL