Which stain is specifically mentioned for its use in the cytological examination of sputum?

Methylene blue is a vital stain commonly used in cytological examinations, particularly for sputum samples. It functions as a vital dye, meaning it can penetrate live cells and provide contrast to the cellular components, making it easier to identify different cell types and cellular abnormalities. In the context of sputum cytology, methylene blue enhances the visualization of cellular details, allowing for the better assessment of respiratory conditions, including infections and malignancies.

Acridine orange is primarily used in molecular biology and research to stain nucleic acids for fluorescence microscopy. Its primary application is not specifically in sputum cytology.

Hematoxylin is an important stain in histology and is often combined with eosin (H&E) for tissue sections, but it is less commonly used in the direct examination of cells from sputum. It is effective for staining nuclei in fixed tissues rather than for analyzing live or fresh sample examinations typically associated with cytology.

Orcein is a dye used to stain elastic fibers and can identify certain structural components in tissues rather than focusing specifically on the cytology of sputum.

The choice of methylene blue aligns with the requirements for effectively visualizing cells in sputum, revealing important details that facilitate the diagnosis of respiratory disorders.