Gram stain Flashcards
(10 cards)
gram staining is an example of which type of staining?
differential stain
what is the primary stain used in Gram staining?
crystal violet
what is the function of iodine in Gram staining?
mordant
which type of bacteria retains the crystal violet stain after alcohol treatment?
gram-positive
gram-positive bacteria have a thick layer of which component in their cell wall?
peptidoglycan
gram-negative bacteria have an outer membrane rich in which component?
Lipopolysaccharide
what color do gram-negative bacteria appear after gram staining?
pink
which of the following is a common gram-positive bacterium?
- E. coli
- Lactobacillus
- salmonella
- pseudomonas
Lactobacillus
which of the following is a common Gram-negative bacterium?
- Staph. aureus
- Bacillus subtilis
- E. coli
- Clostridium
E. Coli
why do gram-negative bacteria lose the crystal violet stain?
- thin peptidoglycan layer
- high lipid content in the outer membrane
- presence of teichoic acids
- both a and b
both a and b