Bioscientist : Jurnal Ilmiah Biologi
Vol. 14 No. 3 (2026): September

Evaluation of Centrifugation Using 4% NaOH for Acid-Fast Bacilli Detection and Ziehl–Neelsen Smear Quality in Sputum Specimens with Negative Rapid Molecular Test Results

Annisa Nazla Sahfiya (Universitas Islam Negeri Sumatera Utara)
Ulfayani Mayasari (Universitas Islam Negeri Sumatera Utara)
Leni Widiarti (Universitas Islam Negeri Sumatera Utara)



Article Info

Publish Date
09 Aug 2026

Abstract

This study aimed to evaluate the effect of centrifugation with 4% sodium hydroxide (NaOH) on acid-fast bacilli (AFB) detection using the Ziehl–Neelsen method in sputum specimens with negative Molecular Rapid Test (MRT) results. This laboratory-based experimental study employed a paired design involving 50 sputum specimens with negative MRT results. Each specimen was examined using the Ziehl–Neelsen method before and after centrifugation with 4% NaOH. The primary outcome was the change in AFB detection results, while smear appearance was descriptively assessed based on background clarity and the presence of debris. All specimens (50/50; 100%) remained AFB-negative both before and after centrifugation, indicating that centrifugation with 4% NaOH did not alter AFB detection outcomes. Descriptively, centrifuged smears showed cleaner backgrounds and less debris, which facilitated microscopic examination; however, smear quality was not evaluated using a quantitative scoring system. Therefore, centrifugation with 4% NaOH did not improve AFB detection by the Ziehl–Neelsen method in sputum specimens with negative MRT results. Nevertheless, centrifuged smears appeared visually cleaner during microscopic examination, suggesting a potential benefit for specimen preparation that requires further validation using standardized quantitative assessment.

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Journal Info

Abbrev

bioscientist

Publisher

Subject

Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Education Immunology & microbiology Social Sciences

Description

Bioscientist : Jurnal Ilmiah Biologi (BJIB), receiving and publishing article in the form of research (scientific article) in the field of biology education and utilization of biological research in learning. Moreover, this journal bridges the gap between research and practice, providing ...