Laboratory Diagnosis Flashcards
What is the wavelength used when checking for M. audouinii infections on Wood’s lamp?
365nm
What is the cleanser used on skin and nails before sampling?
70% isopropyl alcohol
What is the most sensitive method used for isolating blood and bone marrow?
Isolator tube method
What refers to the system that is used in the isolator tube method?
lysis centrifugation system
What is the method used for isolating blood and bone marrow that uses a biphasic system (broth and agar)?
Septi-check method
True or False.
Blood culture bottles are used for specimen collection.
False (blood culture bottles is NOT RECOMMENDED)
2 drops of CSF on laboratory diagnosis are used for?
- India ink preparations
- Latex agglutination
What is used to digest respiratory specimens?
N-acetyl-L-cysteine
On KOH preparations, what is added for the rapid breakdown of cellular debris and requires no heating?
Dimethyl sulfoxide
On KOH preparations, what fluorescent dye is added that makes fungal elements to be apple-green or blue-white in color?
Calcofluor white
What component of Lactophenol Cotton Blue stains the chitin found in the fungal cell walls?
Cotton Blue
What component of Lactophenol Cotton Blue preserves fungal structures?
Lactic acid
What negative stain is used to examine CSF for the presence of C. neoformans?
India ink
Identify the tissue stain.
- polysaccharides
- color of fungal element: purplish-red or magenta
Periodic Acid-Schiff
Identify the tissue stain.
- melanin
- color of fungal element: dark brown, black
Fontana-Masson
What test for molds uses hair fragments that are floated on sterile water supplemented with 10% yeast extract?
Hair perforation test
What test for molds uses Christensen agar as the culture media for differentiating T. mentagrophytes and T. rubrum?
5-day Urease Test
What is the result when a 5-day Urease Test indicates pink or fuchsia in its results?
Positive (T. mentagrophytes)
What test is used to differentiate M. canis and M. audouinii?
Growth on rice grains
What is the most important and easiest to perform for yeast identification?
Germ tube production