May Grunwald's Blood Stains are basic and acidic dyes which induce multiple colours when applied to cells. The basic component of white cells (i.e cytoplasm) is stained by the acidic dye and they are described as eosinophilic or acidophilic. The acidic components (e.g. nucleus with nucleic acid) take blue to purple, shades of the basic dyes and they are called basophilic. The neutral components of the cell are stained by both the dyes.