Is Giemsa stain acidic or basic?

Giemsa stain is a differential stain. It is composed of eosin and azure, both of which are acidic dyes, and methylene blue, which is a basic dye. The acidic dyes eosin and azure stain the basic cellular components such as cytoplasm and granules among others. The basic dye methylene blue stains the acidic components of the cell, particularly the nucleus.