Common Stains Used For Microscopic Visualization Flashcards
Most commonly used stain in clin. Microbiology lab.
Gram stain
What are the sequential components of gram stain?
V- crystal violet (primary)
I- Gram Iodine (mordant/fixative)
A- Acetone alcohol (decolorizer)
S- Safranin (counterstain)
T or F
In gram stain, crystal violet is the primary stain. It should be done in 1 min.
Both statements are True
In Gram stain, what is the mordant/fixative? How long does it take?
Gram iodine-1 minute
T or F
Alcohol acetone is the decolorizer in gram stain, and it should be done quickly and need to rinse.
True
Couterstain in gram stain.
Safranin (30s)
T or F
In gram stain (rinsing with water between in each step is not necessarily.
False- it is required
(Gram stain)
Bacteria is initially stain ___ by the crystal violet, which is bound to the cell wall with the aid of ____
Purple, iodine
(Gram stain)
When decolorizer applied to gram ____ type of cell wall structure, the ______ ______ wash out of the cell.
Negative, crystal violet
Why is Gram negative color pink in gram staining?
Because the decolorizer washed out the primary stain, which Safranin serves as counter stains, who takes up the color pink by gram-negative bacteria.
T or F
(Gram stain)
Gram positive will retain the primary crystal violet stain during decolorizing treatment and appear purple.
True
T or F
(Gram stain)
Cells in direct smear from a patient specimen, like epithelial cells, WBC, RBC should appear purple (positive) if gram stain was performed correctly.
False pink (negative)
4 major steps in staining.
Primary stain
Mordant stain
Decolorization
Counter/secondary stain
Stain that enhances the primary stain to absorb properly.
Mordant stain
Remove the primary stain and most crucial.
Decolorization
Fix the smear and slides
Fixation
General rule:
All cocci are gram positive except
Neisseria, Moraxella, Veillonella
(They are gram negative)
(MNeV)
General rule:
All bacilli are negative except
“BLLaCCMENPro” (positve bacilli)
- Bacillus
- Listeria
- Lactobacillus
- Clostridium
- Corynebacterium
- Mycobacterium
- Erysipelothrix
- Nocardia
- Propionibacterium