Eosinophils have larger, more 3-dimensional granules than those seen in neutrophils. In peripheral blood smears, eosinophils are normally bi-lobed. This does not necessarily hold true in cytospins and should not be used solely to differentiate an eosinophil from a neutrophil.
In a well-stained smear, the orange color of eosinophil granules is easily observed, which easily distinguishes eosinophils from neutrophils. However, when the slide is not stained appropriately, observing the granule size will aid in the identification of the granulocyte. An eosinophil is indicated by the arrow in the right image.
