Ziehl-Neelsen Staining

Ziehl-Neelsen staining is a laboratory technique used to identify certain bacteria, notably tuberculosis bacteria, in tissue samples or sputum. The process involves applying a special dye called carbol fuchsin, which penetrates the waxy outer layer of these bacteria. The slide is then heated to help the dye stick. After rinsing, a decolorizing agent is used to remove dye from other cells, but the bacteria retain the dye due to their unique cell wall. A counterstain is applied to others for contrast. Under a microscope, the targeted bacteria appear bright red or pink against a blue background, aiding diagnosis.