A variation on this staining method is used in mycology to differentially stain acid-fast incrustations in the cuticular hyphae of certain species of fungi in the genus Russula. It is also useful in the identification of some protozoa, namely Cryptosporidium and Isospora. The Ziehl–Neelsen stain can also hinder diagnosis in the case of paragonimiasis because the eggs in an ovum and parasite sputum sample (OnP) can be dissolved by the stain, and is often used in this clinical setting because signs and symptoms of paragonimiasis closely resemble those of TB.
A typical AFB stain procedure involves dropping the cells in suspension onto a slide, then air drying the liquid and heat fixing the cells. The slide is flooded with Carbol Fuchsin, which is then heated to dry and rinsed off in tap water. The slide is then flooded with a mild solution of hydrochloric acid in isopropyl alcohol to destain the Carbol Fuchsin, thus removing the stain from cells that are unprotected by a waxy lipid layer. Thereafter, the cells are stained in methylene blue and viewed on a microscope under oil immersion.
Studies have shown that an AFB stain without a culture has a poor negative predictive value. An AFB Culture should be performed along with an AFB stain; this has a much higher negative predictive value.
"Microbiology with Diseases by Body System", Robert W. Bauman, 2009, Pearson Education, Inc.
Morello, Josephine A., Paul A. Granato, Marion E. Wilson, and Verna Morton. Laboratory Manual and Workbook in Microbiology: Applications to Patient Car. 10th ed. Boston: McGraw-Hill Higher Education, 2006. Print.
^Morello, Josephine A., Paul A. Granato, Marion E. Wilson, and Verna Morton. Laboratory Manual and Workbook in Microbiology: Applications to Patient Care. 10th ed. Boston: McGraw-Hill Higher Education, 2006. Print.
^Romagnesi, H. (1967). Les Russules d'Europe et d'Afrique du Nord. Bordas. ISBN0-934454-87-6.
^Largent, D; D Johnson; R Watling (1977). How to identify fungi to genus III: microscopic features. Mad River Press. ISBN0-916422-09-7. p 25.