Newcomer Supply Carbol Fuchsin Stain, Ziehl-Neelsen, a crucial element in the AFB Stain, Ziehl-Neelsen is used to demonstrate the presence of acid-fast mycobacteria in tissue sections. Acid-fastness is a physical property of certain bacteria and cellular structures. Carbol Fuchsin Stain, Ziehl-Neelsen, combines phenol and basic fuchsin that works to permeate the lipoid capsule of acid-fast organisms and renders them resistant to acid alcohol decolorization. This product has applications for both the Ziehl-Neelsen and Fite AFB staining procedures. Shelf Life is 2 years from date of manufacture. Store at 15-30°C.