Under the National Tuberculosis Programme, Ziehl-Neelsen method (ZN) is the recommended procedure for AFB staining. However, at the Peripheral Health Institutions, the applicability of this procedure appears to be adversely affected due to non- availability of alcohol for heat fixing, heating and decolourisation steps. Hence, it has become necessary to look for procedures when the use of alcohol could be avoided completely. In this study, three different methods of cold staining, wherein the use of alcohol is avoided, have been tried in 489 sputum specimens. One set of smears was fixed with acetone (CSB method), the second set with candle flame (CSD) and third set was not fixed (CSC). All were stained by a modified cold staining procedure. The (a) sensitivity (b) specificity (c) degree of agreement with culture and the standard ZN method and also (d) applicability of these methods, were studied. All the specimens were subjected for culture and ZN smear examinations. ZN method was significantly superior to other methods. As far as the agreement with culture is concerned, ZN method was found to be superior to CSB method by 29.26%, to CSC method by 24.3% and to CSD method by 31.7%.

The sensitivity and specificity of various methods were: ZN-76.1%, 98.4%, CSB-72%, 96.6%, CSD-72.7%, 96% and CSC-76.6%, 96.9% respectively.