Afb Fluroscence Microscopy Pleural Fluid

AFB testing may be used to detect several different types of acid-fast bacilli, but it is most commonly used to identify an active tuberculosis (TB) infection caused by the most medically important AFB, Mycobacterium tuberculosis. Mycobacteria are called acid-fast bacilli because they are rod-shaped bacteria (bacilli) that can be seen under the microscope following a staining procedure in which the bacteria retain the color of the stain after an acid wash (acid-fast). A few different tests may be used to help identify AFB as the cause of an infection: An AFB smear is used as a rapid test to detect mycobacteria that may be causing an infection such as tuberculosis. The sample is spread thinly onto a glass slide, treated with a special stain, and examined under a microscope for "acid-fast" bacteria. This is a relatively quick way to determine if an infection may be due to one of the mycobacteria, such as M. tuberculosis. AFB smears can provide presumptive results within a few hours and are valuable in helping to make decisions about treatment while culture results are pending. However, this rapid test is less sensitive than culture to diagnosis a mycobacterial infection. The testing can narrow the identification to a complex of mycobacteria a combination, of which M. tuberculosis is the most common.