Distinguishing bacteria by cell walls
Certain properties of cell wall result in different staining
reactions. Gram-positive, Gram-negative, and acid-fast bacteria can be distinguished on the basis of these reactions.
Gram-positive bacteria
The cell walls in Gram-positive bacteria has a relatively thick layer of peptidoglycan 20 to 80 nm across. Chemical analysis shows that 60 to 90 percent of the cell wall of a Gram-positive bacterium is peptidoglycan