The buffer used in the Wright-Giemsa staining protocol needs to be pH 6.8 or results will be unsatisfactory. If the buffer is too acidic the stain will be too red and nuclei will be too light; if it is too basic the stain will be too blue and cytoplasmic detail will be indistinct.
Stain results with Wright-Giemsa stain:
Red blood cells should appear tan-pink
Leukocyte nuclei should appear reddish-purple
Neutrophil granules should appear reddish to pink lilac
Eosinophil granules should appear bright red to orange
Basophil granules should appear dark reddish purple
