What is the consequence of using alcohol in the gram staining process?

Using alcohol in the gram staining process primarily serves to decolorize certain bacteria. After the initial crystal violet and iodine staining, alcohol acts as a decolorizing agent, removing the dye from gram-negative bacteria, which have a thinner peptidoglycan layer in their cell wall. This process allows for the differentiation between gram-positive and gram-negative bacteria based on their cell wall structure.

Gram-positive bacteria, with their thicker peptidoglycan layer, retain the crystal violet stain during the alcohol wash. In contrast, gram-negative bacteria lose the crystal violet and can then be counterstained with safranin, appearing pink under a microscope. This step is critical in identifying the type of bacteria present during the gram staining process, making it a key consequence of using alcohol in the procedure.