According to Ziehl-Neelsen

Most commonly known method for detecting TB bacteria according to Ziehl-Neelsen. This method enables rapid and easy staining of acid fast bacterial strains, such as Mycobacteria, Nocardia, Rhodococcus, Dietzia and Gordonia. TB-Stain ECO kit is a phenol–free, environment-friendly alternative for TB-Stain Hot kit.