Place the numbered smears  on a staining rack in batches (maximum 12).  Ensure that the slides do not touch each  other

Flood entire smear with  auramine O and allow to stain for 15 minutes, ensuring that staining solution remains on  smears. Do not heat and do not use filter paper strips

Rinse with distilled  water and drain. Tap water contains chlorine which may interfere with fluorescence

Decolourise with 3%  acid-alcohol for two minutes

Rinse with distilled water and drain

Flood smears with either potassium permanganate or acridine orange and allow to counterstain for two minutes. Time is critical with potassium permanganate because counterstaining for longer may quench the fluorescence of acid-fast bacilli

Rinse with distilled water and drain

Allow smears to air-dry. Do  not blot. Read as soon as possible after staining