A novel method of staining acid-fast bacilli in sputum containers.
OBJECTIVE
Making centrifuged deposit smears from sputum to detect acid-fast bacilli (AFB) is considered hazardous. We carried out this study to stain the centrifuged deposits with carbol-fuchsin in sputum containers and to decolourize and counterstain their smears made on glass slides.


METHODS
The centrifuged deposits of 180 sputum samples from pulmonary tuberculosis patients were used for making smears (initial deposit smears) and staining by Ziehl-Neelsen (ZN) method for the detection of AFB. Each of the sputum deposit was then treated with one ml of 1 per cent carbol-fuchsin and a smear made between 2 to 3 h was then decolourized and counterstained by the same procedures followed in ZN method (2 h stained deposit smear). The coded initial deposit smears and the corresponding 2 h stained deposit smears were read by the same readers and the results compared.


RESULTS
One hundred and fifty (70 positive and 80 negative) 2 h stained deposit smears were compared with initial deposit smears and the difference was not statistically significant.


CONCLUSIONS
Centrifuged deposits of sputum in sputum containers can be stained by carbol-fuchsin within 2-3 h and their smears made subsequently on glass slides can then be decolourized and counterstained by the procedures followed in ZN method for detection of AFB by light microscopy.
Selvakumar
N
N
Tuberculosis Research Centre (ICMR) Chennai, India. selvakumar.nagamiah@gmail.com
Ravikumar
D
D
Sivagamasundari
S
S
Gopi
P G
PG
Narayanan
P R
PR
D002498:Centrifugation; D006801:Humans; D008853:Microscopy; D009161:Mycobacterium / Q000302:isolation & purification*; D012394:Rosaniline Dyes; D013048:Specimen Handling / Q000379:methods*; D013183:Sputum / Q000382:microbiology; D013194:Staining and Labeling / Q000379:methods*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis*
D012394:Rosaniline Dyes; C006898:carbol-fuchsin solution