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yr 12 Biology > Gram Staining > Flashcards

Flashcards in Gram Staining Deck (3)
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1
Q

Process of gram staining (4)

A
  1. Apply crystal violet (purple dye)
  2. Apply iodine (mordant)
  3. Alcohol wash (decolorisation)
  4. Apply safranin (colourisation)
2
Q

Why does the purple dye not stick the negative gram?

A

It dyes the outer membrane but the alcohol breaks this down leaving the peptidoglycan exposed exposed. This is what the pink dye sticks to

3
Q

Difference between gram positive and gram negative (structural)

A

Gram positive have a thick outer layer of peptidoglycan whereas gram negative have a thin layer of peptidoglycan surrounded by an outer membrane