Fluorescence Microscopes

Auramine-Staining using Flourescene Microcopy

Staining    of smear preparations for diagnosis of tuberculosis with fluorescence microscopy.

Dr. Harald Hoffman, M.D.
-Head of the WHO Supranational Reference Laboratory IML, Gauting Germany

My name is Harald Hoffman I’m head of these super national tuberculosis reference laboratory in Gauting Germany, I’d like to you how fluorescence microscopy techniques can help you combat tuberculosis one of mankind’s most serious infectious diseases those cases of tuberculosis affect people in developing countries that have only limited financial resources but which need a simple method for verifying pathogens both quickly and reliably we are actives in these regions as a WHO reference laboratory using fluorescence microscopy to accurately identify the disease you can easily detect the tuberculosis bacteria at a glance by staining preparations with RME this process is much easier than using conventional zeal nilson staging, first mark your microscope slide as usual and streak the material as evenly as possible on the surface then fix the air-dried smear with heat for staining use a solution with or amine o that settles in the cell wall of bacteria keep preparations covered with solution until the end of the 20 minutes staining time, non acid-fast bacteria fade when you subsequently treat them with a mixture of acid an alcohol whereas acid-fast tuberculosis bacteria retain the stain rinse the alcohol thoroughly with distilled water next use potassium permanganate, methylene blue or even ordinary ink for counter staining allow the prepared samples to air dry under the fluorescence microscope you will see any tuberculosis bacteria contrasted against a dark background as luminous rods go get a negative result if you don’t find any acid passed rods in at least 100 to 300 fields of view because fluorescence microscopy provides you with particularly good contrast you can identify samples very quickly indeed effortlessly processing up to 50 preparations in one day.