Gram-negative 
        bacteria stain pink with the gram stain procedure. The Gram-negative cell 
        wall is composed of a thin, inner layer of peptidoglycan and an outer 
        membrane consisting of molecules of phospholipids, lipopolysaccharides 
        (LPS), lipoproteins and sutface proteins. The 
        lipopolysaccharide consists of lipid A and O polysaccharide.