A novel method of staining acid-fast bacilli in sputum containers

摘要

Background & objectives: Making centrifuged deposit smears from sputum to detect acid-fastudbacilli (AFB) is considered hazardous. We carried out this study to stain the centrifuged depositsudwith carbol-fuchsin in sputum containers and to decolourize and counterstain their smearsudmade on glass slides.udMethods: The centrifuged deposits of 180 sputum samples from pulmonary tuberculosis patientsudwere used for making smears (initial deposit smears) and staining by Ziehl-Neelsen (ZN)udmethod for the detection of AFB. Each of the sputum deposit was then treated with one ml ofud1 per cent carbol-fuchsin and a smear made between 2 to 3 h was then decolourized andudcounterstained by the same procedures followed in ZN method (2 h stained deposit smear). Theudcoded initial deposit smears and the corresponding 2 h stained deposit smears were read by theudsame readers and the results compared.udResults: One hundred and fifty (70 positive and 80 negative) 2 h stained deposit smears wereudcompared with initial deposit smears and the difference was not statistically significant.udInterpretation & conclusion: Centrifuged deposits of sputum in sputum containers can be stainedudby carbol-fuchsin within 2-3 h and their smears made subsequently on glass slides can then beuddecolourized and counterstained by the procedures followed in ZN method for detection of AFBudby light microscopy.