Butyrate Esterase is a stain which is specific for white blood cells of the Monocytic proliferation line. It is commonly used in the diagnosis of leukemia when staining touch preparation type slides of bone marrow. It is instrumental in the diagnosis of monocytic leukemias and the myelomonocytic variant of acute myelocytic leukemia (FAB classification M4).
References
Butyrate esterase Wikipedia(Text) CC BY-SA