The most appropriate stain to use to identify a bacterial species that produces thick, waxy cell walls is?

Answer 1

I think that would be the Ziehl-Neelsen stain, because it identifies mycobacteria, known for its thick, waxy cell wall. This stain is also called acid-fast stain.

Answer 2

The only bacteria I know that has a thick coat will be Tuberculosis Bacilli. For these, the identification staining technique will be Ziehl Neelson stain. Latest ZN technique employs cold staining method, however, I always feel safer to flame it so as to allow the stain to penetrate the outer bacilli coat.

Bear in mind though, if it is leprosy bacilli, the above ZN technique will not apply. Instead, you may like to perform Wade-Fite method which stains the leprosy bacilli pretty well.