Question

which is the principle of gram stain

Answer 1

gram stain technique is way to recognize that a bacteria is pathogenic or not ...
....... if the bacteria is pathogenic it will change it colour of green or purple in presence of alcohol

Answer 2

principle of Gram staining is the properties of certain bacteria cell walls to retain the crystal violet dye. The cell walls for Gram-positive microorganisms have a higher peptidoglycan and lower lipid content than Gram-negative bacteria