Tuberculosis (TB) is on the increase world wide. It is thought that approximately 1/3rd opf the worlds population has latent TB and cause 2-3 million deaths per year. The rise of resistant strains make this a serious threat in the west In Africa TB is becoming the most common cause of death of HIV infected people. Although in people with AIDs the TB can infect many other other organs than the lungs, TB is spread through through coughing. Several related organisms cause TB Mycobacterium tuberculosis, M. bovis and M. africanum are the main species. Links on the web, such as http://www.patient.co.uk/showdoc/40000364/, and those on our site, are good resources for information

The bacterium (see http://www-micro.msb.le.ac.uk/video/Mtuberculosis.html) is usually seen with standard stains (this image is taken from that site) The gram positive bacteria have the speciofic property of being acid fast, ie some of the stains cannot be extracted with low pH and this property is used in the stain for tranmission and fluorescence.
A simple flourescence stain is auromine O.

This image of Mycobacterium tuberculosis (slide provided by Prof. Sanjeev Krishna ,Cellular and Molecular Medicine - Infectious Diseases St. George's Hospital Medical School London) was taken like all the florescence images on this site on the SMR microscope using a x 40 objective