Recognizes a myeloid associated differentiation antigen in the cytoplasm of mature granulocytes. It shows no reactivity with any other cell type in human tissues. Markers of myeloid cells are useful in the identification of different levels of cellular differentiation. It reacts with early precursor and mature forms of human and monkey myeloid cells. This MAb is useful for the detection of myeloid leukemias and granulocytic sarcomas. It can be used as a marker of granulocytes in normal tissues or inflammatory processes.