Myeloid membrane markers. I. Expression of marker antigens specific for murine granulocytes and their precursor cells.

Bone marrow cells were investigated by immunoelectromicroscopy and by quantitative photometric immunoradioautography with a rabbit antiserum against murine bone marrow cells. The serum was absorbed with murine spleen, liver and thymus cells until it no longer reacted with thymocytes and lymph node cells in a quantitative complement fixation test. The antiserum stained granulopoietic but not erythropoietic or lymphopoietic cells. The density of the myeloid antigen on single cells increased with the differentiation from immature to mature granulopoietic cells. While the increase of label was statistically not significant at the level of differentiation from promyelocyte to myelocyte and metamyelocyte to band neutrophil, there was a remarkable gain of label from myeloblast to promyelocyte and from band neutrophil to segmented neutrophil. This was evident under the electron microscopy using peroxidase-labeled antibodies and could be measured quantitatively with photometric immunoradioautography using 125I-labeled antibodies.