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

Question

Quizplus · Accepted Answer

The critical step in differentiating gram-positive cells from gram-negative cells is the alcohol-acetone (decolorizing) step. Gram-negative cells will lose their purple color when exposed to alcohol, whereas gram-positive cells will retain their purple color due to the thick peptidoglycan layer in their cell wall. Therefore, the alcohol-acetone step helps to distinguish between the two types of bacteria.

Which Step in the Gram Stain Is the Critical Step