Innovation in acid-fast staining methods: A comparative study of a modified staining rack, a conventional rack and an...

Manual acid-fast staining often results in specimen slippage, inaccurate positioning, and increased biosafety risks. This study evaluated a modified staining rack incorporating a slide-positioning device and an adjustable tilt function to improve the stability and safety of manual acid-fast staining. A total of 142 clinical specimens (70 sputum, 30 bronchoalveolar lavage fluid, 32 pleural effusion and 10 stool specimens) were stained using the modified rack, a conventional rack, and a BSZ-GT116 fully automated stainer. The single-batch staining time with the modified rack was 935.33 ± 20.91 s, 19.3% shorter than that of the conventional rack (1159.08 ± 24.70 s) and comparable to that of the automated stainer (900 s). The proportion of intact smears was 95.77% with the modified rack, versus 91.55% with the conventional rack and 86.62% with the automated stainer. The overall staining quality score for the modified rack was 3.71 ± 0.57, with no significant difference among the three methods (P = 0.506). In the biosecurity assessment, the modified rack demonstrated superior performance. Significant differences emerged across the three methods for both paper contamination rate (χ² = 30.72, P < 0.001) and contamination severity (F = 131.12, P < 0.001). The modified rack reduced unit costs by 23.9% versus the conventional rack (USD 1.24 vs. 1.63). However, the BSZ-GT116 automated stainer's cost-effectiveness remained utilization-dependent; at 20,000 annual tests, costs equaled those of the modified rack. Overall, the modified rack combines manual flexibility with greater efficiency and lower biosafety risks, making it suitable for promotion in resource-limited laboratories.