1. Are acid-fast negative cells stained by carbolfushin? if so, how can this be a differential stain?

2. What kind of bond is bound by charges?

3. How does heating a bacterial smear during a ZN (Ziehl-Neelsen) stain promote entry of carbolfushsin into the acid fast cell wall?

4. why do you suppose the acid-fast stain is not as widely used as the gram stain? when is it more useful than the gram stain?