Step 3 Decolorize with alcohol briefly -about 20 sec 酒精脱色20秒 Gram-positive cells are purple;gram- negative cells are colorless Step 4 Counterstain with safranin for 1-2 min 沙黄复染1-2分钟 Gram-positive(G+)cells are purple;gram-negative FLASH Gx (G)cells are pink to red酒精脱色20秒 沙黄复染1-2分钟 FLASH