[Elizabeth_Zeibig]_Clinical_Parasitology__A_Practi(z-lib.org)

CHAPTER 2 Specimen Collection and Processing
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PROCEDURE 2-8
MODIFIED ACID-FAST STAIN
Step No. Reagent Purpose Time
1 Kinyoun carbol fuchsin Stain 5 min
2 50% ethanol Rinse Briefly
3 Tap water Rinse Thorough
4 1% sulfuric acid Decolorizer 2 min
5 Tap water Rinse 1-2 min
6 Methylene blue Counterstain 1 min
7 Tap water Rinse 1-2 min
8 Air-dry, examine under oil immersion
NOTE: This procedure may be used for unpreserved specimens or for samples fixed in formalin. The sample should be smeared on the
slide and allowed to air-dry. The slide should be fixed in absolute methanol for 1 minute and allowed to air-dry before proceeding with
this procedure.
PROCEDURE 2-9
CELLOPHANE TAPE PREPARATION
1. Fold the end of a 10-cm piece of transparent tape,
adhesive side out, over the end of a tongue depressor.
It is important not to use frosted tape because it might
mask the appearance of the eggs.
2. Press the adhesive side of the tape firmly against the
perianal region of the patient. Using a rocking motion,
cover as much of the region as possible.
3. Place the tape, adhesive side down, on a clean glass
microscope slide. Avoid trapping air bubbles during
this step.
4. Microscopically examine the slide under low power.
Reduced light is recommended because the eggs will
appear colorless, making them difficult to detect under
high light intensity.
NOTE: Commercial collection kits are also available for use. Each kit contains a plastic collection paddle. In this procedure, the paddle
is used for collection and examination.
PROCEDURE 2-10
PREPARATION OF THICK BLOOD SMEARS
1. Place three small drops of blood onto one end of a clean
microscope slide.
2. Using the corner of a second clean microscope slide as
a stirrer, combine the contents of the three drops of
blood by thoroughly mixing and spreading to a circular
film approximately the size of a dime or nickel.
3. Let the slide air-dry.
4. Remove the hemoglobin by immersing the slide in a
buffer solution before staining or directly during Giemsa
staining.