Ziehl-Neelsen stain

The Ziehl-Neelsen stain is a laboratory technique used to identify certain bacteria, like the one that causes tuberculosis. It uses special dyes to color these bacteria so they can be seen under a microscope. The process involves applying a heat-assisted dye, which penetrates the bacteria's cell walls, then washing away the excess dye. Acid-fast bacteria retain the primary stain and appear bright red, while other cells are counterstained to appear blue. This method helps doctors diagnose infections quickly and accurately by visualizing these specific bacteria in tissue samples or sputum.