AFB testing can be used to identify a variety of acid-fast bacilli, although it is most frequently used to spot an active tuberculosis (TB) infection brought on by Mycobacterium tuberculosis, the most significant AFB from a medical standpoint. Because mycobacteria are rod-shaped bacteria (bacilli) that can be observed under a microscope after a staining method in which the bacteria retain the colour of the stain after an acid wash, they are known as acid-fast bacilli (acid-fast). As the cause of tuberculosis (TB), Mycobacterium tuberculosis and other Mycobacterium species are known as acid-fast bacilli (AFB), an AFB test aids in the detection and identification of these illnesses as well as the monitoring of treatment effectiveness.