[The use of highly dispersed iron particles for increasing the sensitivity of the luminescent microscopic method of determining Mycobacterium tuberculosis].
A highly dispersed ferromagnetic powder obtained by a plasmochemical method (particle size was 100-500 A) was treated by means of an ultrasonic disperser: suspension was added to the trisodium phosphate homogenized and neutralized sputum (0.3 mg of the initial powder per 1 ml of sputum) of patients with various forms of pulmonary tuberculosis. The sputum was then incubated at slight stirring for 40 min and centrifuged; the precipitate was used to prepare smears which were stained with auramine; mycobacteria were detected by luminescence microscopy. The ferromagnetic suspension was found to increase luminescence microscopy sensitivity to 85.4%. The efficacy of the method was 30.8% more than that in the cultivation of infectious material in solid nutrient media.