Pretreatment of plastic Petri dishes with fetal calf serum. A simple method for macrophage isolation.

We have developed a simple method which can recover the highly purified macrophages or monocytes in suspension from mouse peritoneal exudate cells and human perpheral blood mononuclear cells. Plastic Petri dishes coated overnight with heat-inactivated fetal calf serum (FCS) selectively bind macrophages and monocytes. The adherent macrophages and monocytes are easily removed by incubation in phosphate-buffered saline containing 0.2% ethylenediamine tetraacetate (EDTA) and 5% FCS, and recovered as a cell suspension with greater than 95% purity. A small number of isolated cells can restore the mitogenic response to phytohemagglutinin (PHA-P) of macrophages-depleted lymphocytes and can lyse 51Cr-labeled target cells in an antibody-dependent cell-mediated cytotoxicity system. Thus, the method should be valuable for studies of various functions of macrophages and monocytes from different immune tissues of man and animals.