The basophilic granulocyte is typically 9-14 μm in diameter and contains many large, dark purple granules that lie both in the cytoplasm and over the segmented nucleus. The granules contain histamine and other inflammatory mediators. Basophilia can be seen in atopy and in response to infections. Basophilic granulocytes are activated by binding with IgE and/or complement. Chronic myeloid leukemias are sometimes accompanied by basophilia.