Brief Report: Evaluation of Ziehl-Neelsen Slide Restaining with 0.4% Malachite Green for Identifying Cyclospora cayetanensis Oocysts

Abstract

Cyclospora cayetanensis oocysts are commonly identified using Ziehl-Neelsen acid-fast staining. However, slides stored for seveal periods often exhibit color fading, reducing visual clarity and limiting their suitability for training and educational purposes. This study evaluated the effectiveness of restaining with 0.4% malachite green to enhance contrast and visualization of oocysts on faded slides. A quantitative experimental laboratory design was employed. Ten positive slides stored at the Clinical Parasitology Laboratory, Faculty of Medicine Universitas Indonesia, were selected based on the degree of fading and staining thickness. Each slide was restained with 0.4% malachite green for 30 seconds after destaining with methanol. Following drying, slides were examined under a light microscope, and oocysts were manually counted. Restaining restored the background to a bluish-green hue, improving visual contrast and facilitating oocyst identification. Restaining Ziehl-Neelsen slides with 0.4% malachite green is a simple and effective method for enhancing visualization and identification of C. cayetanensis oocysts.