<prompt> Gentian violet colouration of gram positive bacteria is due to ?PeptidoglycanCapsuleCell membraneNone of the above  <response>: Ans. is a i.e., Peptidoglycan GRAM STAINING The gram stain differentiates bacteria into two broad groups :? Gram positive - Resist decolourization and retain primary stain, appear violet. Gram negative - Decolourised by organic solvents, and therefore, take the counterstain, appearing red. 