Color enhanced scanning electron micrograph of human basophils. Basophil is a type of white blood cells. Basophils are the least common of the granulocytes. Basophils contain large cytoplasmic granules which obscure the cell nucleus under the microscope when stained. When unstained, the nucleus is visible and it usually has two lobes. The mast cell, another granulocyte, is similar in appearance and function. Both cell types store histamine, a chemical that is secreted by the cells when stimulated. Magnification @ 8000x, 8x10 print.