Variations in quality of carbol fuchsin stains collected from routine tuberculosis laboratories.
METHODS
In-use carbol fuchsin stains were collected from 10 different routine acid-fast bacilli smear microscopy laboratories.


OBJECTIVE
To examine the variations in the composition of carbol fuchsin stains.


METHODS
Carbol fuchsin concentrations were first determined spectrophotometrically by measuring absorbance at 547 nm. High-performance liquid chromatography (HPLC) separated and quantified the four basic fuchsin homologues: para-rosaniline, rosaniline, magenta II and new fuchsin, and identity was confirmed by mass spectrometry (MS).


RESULTS
Absorbance measurement showed that three of 10 (30%) samples contained insufficient carbol fuchsin (<70%). Wide variations in relative proportions of fuchsin homologues were found.


CONCLUSIONS
The relative abundance of rosaniline + new fuchsin was quite stable among the different laboratories. Spectrophotometry and HPLC/MS are necessary and sensitive tools for monitoring fuchsin quality.
Zhao
Y L
YL
National Reference Laboratory, Beijing Chest Disease and Tumour Hospital, Beijing, China.
Liu
Y H
YH
Jiang
G L
GL
Chan
W Y
WY
Yip
C W
CW
Kam
K M
KM
D002851:Chromatography, High Pressure Liquid; D004396:Coloring Agents / Q000737:chemistry / Q000592:standards*; D006723:Hong Kong; D006801:Humans; D007753:Laboratories / Q000592:standards*; D012394:Rosaniline Dyes / Q000737:chemistry / Q000592:standards*; D013053:Spectrophotometry; D013183:Sputum / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis*
D004396:Coloring Agents; D012394:Rosaniline Dyes; C006898:carbol-fuchsin solution