Gram staining primarily differentiates bacteria based on what property?

Gram staining primarily differentiates bacteria based on what property?

• A. Shape
• B. Cell wall structure
• C. Motility
• D. Metabolic type

Answer: (B)

Gram staining differentiates bacteria by differences in their cell wall structure, especially the thickness of the peptidoglycan layer and whether an outer membrane is present. During the process, crystal violet-iodine locks into the cell wall. When alcohol is applied, the thick peptidoglycan of Gram-positive bacteria traps the dye and remains purple, while the thinner peptidoglycan and outer membrane of Gram-negative bacteria lose the dye and take up the counterstain, turning pink. This staining pattern reflects the underlying cell wall architecture, not the shape, movement, or metabolic capabilities of the bacteria.

Gram staining differentiates bacteria by differences in their cell wall structure, especially the thickness of the peptidoglycan layer and whether an outer membrane is present. During the process, crystal violet-iodine locks into the cell wall. When alcohol is applied, the thick peptidoglycan of Gram-positive bacteria traps the dye and remains purple, while the thinner peptidoglycan and outer membrane of Gram-negative bacteria lose the dye and take up the counterstain, turning pink. This staining pattern reflects the underlying cell wall architecture, not the shape, movement, or metabolic capabilities of the bacteria.