AAT Bioquest

What are acid-fast bacteria?

Posted June 1, 2020


Acid-fast bacteria (also known as acid-fast bacilli or AFB) are microorganisms resistant to acids and/or ethanol-based decolorization procedures common in many staining protocols, hence, the term acid-fast.

One notable example of acid-fast bacteria is mycobacteria, including Mycobacterium tuberculosis who causes the respiratory disease tuberculosis and Mycobacterium leprae that causes the disfiguring disease leprosy. Very few structures are acid-fast, which makes identifying acid-fastness particularly useful in diagnosis.

Additional resources

MycoLight™ Live Bacteria Fluorescence Imaging Kit

MycoLight™ Flow Cytometric Live Bacteria Assay Kit

Madison, B. M. (2001). Application of stains in clinical microbiology. Biotechnic & Histochemistry, 76(3), 119-125.

Almand, E. A., Moore, M. D., & Jaykus, L. A. (2017). Virus-bacteria interactions: an emerging topic in human infection. Viruses, 9(3), 58.