Acidfast Stain: Background and Introduction. Mycobacterium and many Nocardia species are called acid-fast because during an acid-fast staining procedure they retain the primary dye carbol fuchsin ...

These granules were spherical, and stained somewhat paler red than the acid-fast Myco. leprae with the Fite-Faraco modification of Ziehl-Neelsen stain using Harris's hæmatoxylin as counter-stain.