Lesson 1 : Specimen Collection Flashcards
also known as direct wet mount), defined as a slide made by mixing a small portion of unfixed stool (stool
with no added preservatives) with saline or
iodine and subsequent examination of the resultant mixture under the microscope, is to detect
the presence of motile protozoan trophozoites.
Direct Wet Preparation
It is made by
placing a drop of 0.85% saline on a glass slide
(a 3- × 2-inch size is suggested) and mixing with
a small portion of unfixed stool using a wooden
applicator stick or another mixing tool.
A direct saline wet preparation
It is made
to enhance the detail of protozoan cysts.
direct iodine wet preparation
provide the ability to detect small numbers of
parasites that might not be detected using direct
wet preparations.
Concentration techniques
Substances
that preserve the morphology of protozoa and
prevent further development of certain helminth
eggs and larvae.
Fixatives
It has been used for many
years as an all-purpose fixative for the recovery
of protozoa and helminths.
Formalin
It is
comprised of a plastic powder that acts as an
adhesive for the stool specimen when preparing
slides for staining.
Polyvinyl Alcohol
This preservative
can be used for performing concentration techniques and permanent stained smears.
Sodium Acetate Formalin
Other alternatives to mercury-based PVA are the use of substitute compounds containing copper sulfate or
zinc sulfate. The advantage of these formulas is
that they can be used for concentration methods
and permanent stained smears.
Modified Polyvinyl Alcohol
These single-vial fixatives are free of
formalin and mercury and can be used for concentration techniques and permanent stained
smears.
Alternative Single-Vial Systems
To perform this ________________examination, the laboratory must
receive a fresh, unpreserved stool specimen.
Macroscopic Examination.
What kind of examination is used To detect the presence of parasite in a stool pecimen.
Microscopic Examination
The most widely ued edimentation
technique i the formalin–ethyl acetate edimentation procedure. The principle of this technique
is based on specific gravity.
Formalin–Ethyl Acetate Sedimentation Procedure
This technique is also based on difference in pecific gravity between the sample
debris, which in this case is heavy and sink to
the bottom of the test tube, and potential parasite, which are lighter and float toward the top
of the tube.
Zinc Sulfate Flotation Technique
(defined a a microscope slide that
contain a fixed ample that has been allowed to
dry and subequently stained.
Permanent Stains
