Sedimentation method, a good alternative to centrifugation for concentration of acid fast bacilli in developing countries: a preliminary study from western Uttar Pradesh.

Microscopic examination of respiratory specimen for Acid Fast Bacilli (AFB) plays an important role in the initial diagnosis of tuberculosis as well as for monitoring of antitubercular treatment. Direct microscopy of sputum has a low sensitivity.[1] Previous studies have shown that concentration and liquefaction of sputum signiÞ cantly improves the sensitivity of direct microscopy.[2] In the present study, we have compared the sensitivity of direct AFB smears to that with smear made after concentration of the specimen utilizing two different methods, N-acetyl-Lcystine (NALC)-NaOH concentration method and NaOCl liquefaction and sedimentation method, so as to evaluate an easy, less cumbersome, and cost-effective method to improve the sensitivity of direct microscopy for AFB, especially for developing countries and smaller peripheral centers.