Description
Methylene Blue Solution is a 0.3% counterstain used in the Ziehl–Neelsen procedure for acid-fast bacteria.
After carbol-fuchsin staining and acid-alcohol decolourisation, non-acid-fast cells and background material take up methylene blue, while acid-fast organisms retain the red primary stain.
The solution is applied to the decolourised smear according to the staining sequence in the PDF, followed by rinsing, drying and microscopic examination.
