What does auramine rhodamine do?
Fluorescent dyes like auramine-rhodamine bind to the mycolic acid present in them and impart bright yellow or orange fluorescence against a greenish background when viewed using a fluorescent microscope. It is also used to stain all acid-fast organisms including the sporozoan parasites.
What happens if sputum AFB is positive?
If your AFB smear was positive, it means you probably have TB or other infection, but an AFB culture is needed confirm the diagnosis. Culture results can take several weeks, so your provider may decide to treat your infection in the meantime.
Is Mycoplasma tuberculosis acid-fast?
Mycobacterial Diseases Most practitioners choose either the Ziehl-Neelsen or the Kinyoun stain, neither of which will stain Nocardia (unlike the Fite stain). Due to their waxy cell wall components, the bacilli of MTB are acid fast; that is, they retain the red dye, carbol fuchsin, after rinsing with acid solvents.
What if sputum AFB is negative?
A negative AFB smear may mean that no infection is present, that symptoms are caused by something other than mycobacteria, or that the mycobacteria were not present in sufficient numbers to be seen under the microscope.
What is fluorescent staining procedure?
A fluorescent staining procedure has been developed which rapidly, accurately, and economically measures the viability of mycobacterial cells. These cells appear green when viewed under incident ultraviolet illumination. Ethidium bromide enters dead cells and intercalates between the bases of DNA molecules.
Is Mycobacterium tuberculosis gram positive?
First discovered in 1882 by Robert Koch, M. tuberculosis has an unusual, waxy coating on its cell surface primarily due to the presence of mycolic acid. This coating makes the cells impervious to Gram staining, and as a result, M. tuberculosis can appear weakly Gram-positive.
What color is sputum of tuberculosis?
Tuberculosis (TB) If someone has TB, they may cough up green or bloody phlegm. They will also experience symptoms that can include: weight loss. night sweats.