Question

match the gram stain step with the state of the bacteria after the step. instructions crystal violet iodine alcohol safranin gram - positive cells remain purple, and gram - negative cells appear red. gram - positive cells remain purple, and gram - negative cells become colorless. cells stain purple. cells remain purple.

Explanation:

1. Crystal Violet: This primary dye stains all bacterial cells purple regardless of their type.
2. Iodine: It forms an insoluble complex with crystal violet, locking the dye in all cells, so they stay purple.
3. Alcohol: Gram-positive cells have thick peptidoglycan walls that retain the crystal violet-iodine complex, staying purple; Gram-negative cells have thin walls that dissolve, losing the dye and becoming colorless.
4. Safranin: This counterstain colors the now-colorless Gram-negative cells red, while Gram-positive cells remain purple (the darker purple masks the lighter red dye).

Answer:

Crystal Violet → Cells stain purple.
Iodine → Cells remain purple.
Alcohol → Gram-positive cells remain purple, and Gram-negative cells become colorless.
Safranin → Gram-positive cells remain purple, and gram-negative cells appear red.