In the Gram stain,which step is critical in differentiating Gram-positive from Gram-negative cells?

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The critical step in differentiating Gram-positive from Gram-negative cells is the use of ethanol (or a similar alcohol) to decolorize the cells after they have been stained with crystal violet and treated with a mordant. Gram-positive cells have a thicker peptidoglycan layer in their cell wall, which retains the crystal violet-iodine complex and appears purple under the microscope. Gram-negative cells have a thinner peptidoglycan layer, but they also have an outer membrane that contains lipopolysaccharides. This outer membrane is dissolved by the ethanol wash, allowing the crystal violet to leak out of the thinner cell wall and appear colorless. The cells are then stained with safranin, which stains the colorless Gram-negative cells pink or red, while the purple Gram-positive cells remain purple.

In the Gram Stain,which Step Is Critical in Differentiating Gram-Positive