Basophil
A type of leukocyte (white blood cell) with coarse bluish-black granules of uniform size within the cytoplasm and typically a bilobate (two-lobed) nucleus.
Basophils are so named because their cytoplasmic granules stain with basic dyes.
Basophils normally constitute 0.5 to 3% of the peripheral blood leukocytes.
Basophils contain (and can release) histamine and serotonin.
Also called a basophilic leukocyte