MOMA 1 is a useful marker for the identification of macrophage subpopulations in various organs, mostly characterised by a high level of non-specific esterase expression. The staining is particularly noteworthy with the metallophilic macrophages adjacent to the marginal zone of the spleen. The marker is also very suitable for differentiation of non-metallophilic marginal zone macrophages as detected by ER-TR 9. In addition , MOMA 1 detects macrophages at inflammatory sites and is positive with Kupffer cells. The antigen is differentially induced in in vitro derived macrophages depending on the colony-stimulating factor applied (IL-3 > M-CSF > GM-CSF). Application: IHC (f)