Evaluation of sputum smears prepared by different methods
Naganathan, N.; Ganapathy, K.T.; Rajalakshmi, R.
Indian Journal of Medical Research 69: 893-900
1979
ISSN/ISBN: 0019-5340 PMID: 381187 Document Number: 145405
The sensitivities of 4 methods of sputum smear preparation for pulmonary tuberculosis diagnosis were compared: direct smear prepared blindly without marking any selection of portions of sputum specimen; smears from portions of sputum material likely to contain the bacilli; smears made after thoroughly mixing the sputum specimens; and smear prepared from centrifuged deposit after homogenization of sputum with NaOH and concentration by centrifugation. There was practically no difference in the number of positives obtained from different methods. Centrifuged deposit smears were no better than the direct smears. Differences in the methods existed only in the classification of positive smear as to low or high grade.