<prompt> Gram-negative bacteria doesnt take gram stain because it is made ofPolysaccharideLipopolysaccharideTechoic acidNone of the above  <response>: The exact mechanism of gram reaction is not known. The possible reason is: Gram-positive bacteria have a more acidic protoplasm, which accounts for their retaining the basic primary dye more strongly. Dye iodine complex is retained in gram-positive cells by thick peptide glycan mesh and is readily wash through the very thin peptidoglycan layer of gram-negative cells. Ref: Ananthanarayana textbook of Microbiology 9th edition Pgno : 13 