Which step in the Gram stain is the critical step in differentiating gram-positive cells from gram-negative cells?
A) crystal violet
B) safranin
C) alcohol-acetone
D) iodine

Question

Quizplus · Accepted Answer

The alcohol-acetone step is critical because it decolorizes gram-negative cells by dissolving the outer membrane and allowing the crystal violet-iodine complex to be washed out, while gram-positive cells retain the complex due to their thicker peptidoglycan layer.

Which Step in the Gram Stain Is the Critical Step