Gram positive vs gram negative
Gram positive bacteria have a single thick cell wall made of peptidoglycan (50-90% of cell wall). This thick wall stains purple and remains purple throughout the gram staining test. Gram negative bacteria have a thinner layer of peptidoglycan (10% of cell wall), and an additional outer membrane which contains lipids.The outer membrane of gram negative bacteria will stain purple also but it falls off during the gram stain test. Its 2nd wall is what gets stained pink.he trick to remembering the difference between gram positive and gram negative bacteria is to first understand where their naming convention comes from. I have an article follow by a mini game to teach you the difference between gram positive and gram negative bacteria.