Abdul Sattar, Shahid Habib Ansari, Mudasar Hussain, Muzaffar Masood, Abrar Anwar, Ali Raza.
Role of Bleach Sedimentation to Improve the Accuracy of Sputum Smear Microscopy for Diagnosing Tuberculosis.
Ann Pak Inst Med Sci Jan ;10(4):212-4.

Objective: To compare the sensitivity of smear microscopy obtained with smears made directly from respiratory specimens to those from concentrated specimen. Place and duration: The study was conducted at department of Pathology Khawaja M Safdar Medical College/ Abdul Sattar’s Lab, Sialkot from July 2014 to December 2014. Materials & Methods: Sputum samples were collected aseptically. Direct smears were prepared by taking a small portion of purulent part of the sputum with a sterile loop. Concentrated smear was prepared by taking purulent part of sputum and mixing with equal volume of 5% sodium hypochlorite. It was then kept for 15 minutes, centrifuged and sediment used for staining. Both smears were air dried, heat fixed and stained by Ziehl-Neelsen staining technique. The stained slides were examined under oil immersion lens with positive and negative controls. Acid fast bacilli were graded according to International Union against tuberculosis and lung diseases guideline. Cutoff values for Positive AFB were 1- 9/100F = 1+, 1-9/10F = 2+ and 1-9/F = 3+. Results: Out of total 189 samples, 53 samples were positive by direct smear and 63 samples were positive by concentrated smear. Conclusion: Concentration with bleach increased the sensitivity of sputum smear microscopy. This method is very effective in resource limited areas like ours.

PakMediNet -Pakistan's largest Database of Pakistani Medical Journals - http://www.pakmedinet.com