Staining Fecal Smear Flashcards
Why do we need to stain fecal smears?
For the identification of protozoans and sharp definition of the morphologic details of the parasite
Noted for creating fine morphologic detail and stains intestinal protozoa (both trophozoites and cysts) with great detail
Iron Hematoxylin
It is a modification of Gomori stain
Wheatley’s Trichome
It is a routine part of the ova and parasite examination for the
identification of Cryptosporidium, Isospora, and Cyclospora
Modified Acid Fast
In this stain helminth eggs and
larvae may be obscured by excess stain
Iron Hematoxylin
In Wheatley’s Trichome, the background material appears ________ in color and protozoa have a ___________ cytoplasm.
greenish and blue-green to purple, respectively
This is a very good stain for fresh, PVA
or SAF-preserved fecal smears
Iron Hematoxylin
What are the 3 organisms differentiated in Modified Acid Fast?
Cryptosporidium, Isospora, and Cyclospora
This is a very useful stain for fresh and PVA-preserved fecal smear but not with SAF-preserved smears
Wheatley’s Trichome
The Modified Acid Fast retain the carbol fuschin and stain ________ against a _____ background.
bright red to purple and blue, respectively
What are the 3 permanent stains?
Iron Hematoxylin, Wheatley’s Trichome, Modified Acid Fast
In preparing a fecal smear, how many minutes do you fix the fresh stool sample in PVA?
30 minutes or overnight
In preparing a fecal smear, how many minutes do you fix the fresh stool sample in PVA?
30 minutes or overnight
In fecal smear preparation, in what motion do you spread the preserved stool?
Rolling
At what temperature do you allow the fecal smear to dry?
37°C incubator or overnight at room
temperature
TRUE OR FALSE: In staining with Iron Hematoxylin, you place the slide in 85% ethanol for 15 minutes.
FALSE. Because it should be at 70% ethanol for 5 minutes.
TRUE OR FALSE: In staining with Iron Hematoxylin, you wash the slide with running distilled water (constant stream of water into the container) for 10 minutes.
FALSE. Because you should wash the slide with running tap water not distilled.
How many minutes should you place the slide in iron hematoxylin working solution?
4 to 5 minutes
In staining with Iron Hematoxylin, what do you add to the stained area before covering the slide with a coverslip?
Mountant
In what objective do you examine the iron hematoxylin-stained smear microscopically?
oil immersion objective
Before reporting a negative result in an iron hematoxylin-stained smear, how many fields must you examine?
200 to 300 fields
Staining with Iron Hematoxylin is for the assessment of?
- Trophozoites
- Cysts
- Yeast cells
- Pseudo hyphae
- Human cells (Macrophages, PMNs, RBCs)
This is used for the detection of Cryptosporidium, Cyclospora, and other Coccidian
Acid-Fast Stain (Modified Ziehl Neelsen Technique)
When it comes to acid-fast stains, how long do you fix the air-dried smear in methanol?
2-3 minutes
In which staining method do you stain the feces with cold carbol-fuchsin for 5-10 minutes?
Acid-fast stain (Modified Ziehl-Neelsen Technique)
In which staining method do you stain the feces with cold carbol-fuchsin for 5-10 minutes?
Acid-Fast Stain (Modified Ziehl Neelsen Technique)
In Acid-Fast Stain, this is added as a decolorizer.
acid-alcohol
TRUE OR FALSE: In Acid-Fast stain, you counterstain with 0.25% malachite green or methylene blue for 30 seconds.
TRUE
What can inexperienced microscopist miss easily?
Oocysts
Oocysts are elongated ellipsoidal in shape, one _____ or two _____appear inside.
sporoblast and sporocysts, respectively
A stool smear stained in this stain shows the size difference and staining characteristics between cyclospora cayetanensiis and cryptosporidium spp.
modified acid-fast stain
