What type of cell stains with acid during microscopic preparation?

The correct answer is eosinophil, which is a type of white blood cell that stains well with acidic dyes such as eosin. This characteristic is due to the presence of granules in the eosinophil's cytoplasm that contain proteins which are acidic in nature. When these cells are prepared on a slide for microscopic examination, they take up the eosin dye, giving them a distinctive pink or reddish appearance.

Eosinophils play a significant role in the immune response, particularly in combating parasitic infections and in allergic reactions. The ability to stain with acid indicates the presence of specific components in their cytoplasm that are responsive to acidic staining techniques, providing valuable information about their abundance and morphology in various medical conditions.