Role of Bleach Concentration Method for Detection of Acid-fast Bacilli (AFB) in Sputum using Conventional Ziehl-Neelsen (ZN) Staining Technique

Sputum microscopy is the most important tool for detection of Mycobacterium tuberculosis in peripheral laboratories. Sodium hypochlorite concentration technique prior to sputum may improve AFB bacilli over direct Ziehl Neelsen’s staining method. A prospective study was conducted at Kasturba Medical College, Manipal. Consecutive samples were collected 3 months. ZN stained smears made directly fresh specimens and that processed with 3.5% sodium (NaOCl), from each patient. Then, observed under light microscopy. total 239 collected. The yield positive after NaOCl centrifugation higher than stain. percentage increase 3.3% (8/239). Bleach can help increasing positivity smear.