Background: Existing methods for the preparation of panel slides necessitate handling high-grade acid-fast bacilli positive sputum samples.
Objective: To compare panel slides prepared using the phenol ammonium sulphate sediment (PhAS) method with those prepared using the N-acetyl-L-cysteine (NALC) method in proficiency testing.
Methods: Pooled sputum specimens of known smear-positives and -negatives were divided into two parts: one part was used for preparing panel slides using the NALC method and the other using PhAS, a non-hazardous method. Respectively 413 and 384 smears of different grades were prepared in three batches using the PhAS and NALC methods. Smear grade and quality were recorded by 121 microscopists during proficiency testing in different states. Agreement between reference and reported results was analysed using the kappa test.
Results: The overall agreement was 96% for the PhAS method and 91% for the NALC method. There were 37 errors using the NALC method compared to 21 for the PhAS method (P < 0.223). Smear quality was equally good in both methods; however, the cell count was significantly higher in the PhAS than in the NALC method.
Conclusion: The PhAS method, a non-hazardous procedure with good-quality smears, may be further explored for the preparation of panel slides.