Journal of Pure and Applied MicrobiologyVol. 2 No. 2

Evaluation of Rapid AFB Cold (RAC) Staining Method for Sputum Smears Treated with Bleach Ammonium Sulphate

Sherafin Jancy Vincy, M. Chandrasekar* and P. Venkatesan

Medical Laboratory Technology Division, P.G. & Research Department of Advanced Zoology and Biotechnology, Loyola College (Autonomous), Chennai - 600 034, India.

Received on 10 April 2008 and accepted on 21 July 2008



In the present study, a total of 570 smears were prepared from 190 sputum samples treated with 5% Bleach ammonium sulphate(BAS), which were stained using Rapid – AFB Cold (RAC) and Hot Ziehl – Neelsen (HZN) staining methods. With Direct control (DC) used as gold standard, RAC smear microscopy demonstrated a sensitivity and specificity of 78% and 95% respectively, compared to 79% and 92% respectively for the HZN method. Comparison of smear results obtained from RAC and HZN methods were statistically highly significant (P < 0.0001). RAC staining method was found to be a suitable alternative to the HZN staining method in diagnosing Tuberculosis (TB) by smear microscopy in peripheral TB centers.

Keywords : Cold stain, Ziehl- Neelsen stain, Bleach Ammonium Sulphate, Tuberculosis.