LESSON 5: DIRECT MICROSCOPIC EXAMINATION Flashcards
It may provide the physician with a rapid diagnosis and information regarding the possible needed for treatment
Direct Microscopic Examination
A differential staining technique based on bacterial cell wall structure - classified bacteria as:
1.
2.
Gram positive
Gram negative
5 procedure for gram stain
1.
2.
3.
4.
Prepare the smear
crystal violet (primary stain)
iodine (mordant)
Acetone-alcohol (decolorizer)
safranin (counter stain)
In preparing the smear:
make an evenly ________ smear
thin
In preparing the smear:
air dry and or heat fix by passing through a flame _______
2-3 times
In preparing the smear:
allow to ______
cool
In preparing the crystal violet
flood for _______ minute
1 minute
In preparing the crystal violet
wash gently with _________
water
In preparing the crystal violet
pour _____ excess water
off
In preparing the acetone-alcohol (decolorizer)
decolorizer for ______ seconds until the alcohol runs almost clear
5-10 seconds
In preparing the acetone-alcohol (decolorizer)
be careful _________ decolorize
not to over
Fungal elemnts appear as gram positive or gram variable
Gram stain
examine for budding cells to confirm if yeast cells and not bacteria or artifact
Gram stain
The polysaccharide capsule of crytptococcus spp. exclude the ink particles giving a clear halo around the organism in a semi opaque background
India ink
use for cerebrospinal fluid (CSF)
India Ink
It is negative stin: stain is the background, yeast cells remain unstained
india ink
By using india ink it should be on what field?
High power field
In quality control its is recommended that:
- to clean the slide using:
1.
2.
3
lens tissue
gauze with alcohol then dry
heating or passing the slide under a flame
Direct examination of specimen for rapid detection of fungal elements
KOH wet mount
Direct examination of specimen by using __________
clearing agent (KOH)
10% KOH : ______, ______ and ________
Skin scrapings and other specimens
20% KOH: _______, ______, _________
Nail, Hair, Tissue
A compound that stains the fungal cell wall can be helpful in revealing fungal elements in wet mounts when examined under a fluorescence microscope.
KOH with Calcoflour white
KOH with calcoflour white examine under what microscope?
Fluorescence microscope
