Detection and enumeration of monocytes in human blood with peanut agglutinin

Abstract Binding of peanut agglutinin (PNA) to normal human peripheral blood mononuclear cells was analyzed on a cell sorter, and compared to the binding of the monocyte specific monoclanal antibodies Mac-1 and Leu-M3. Each of the reagents labeled 9–11% of the mononuclear cells and similar binding patterns were observed. Of the PNA + cells, 67% adhered to plastic petri dishes, whereas 76% of Mac-1 + cells were adherent. No competition for binding was observed between PNA and Mac-1 on the one hand, or PNA and Leu-M3 on the other. In double staining experiments, about 10% of the cells, comprising 80% of the monocytes, were PNA + Leu-M3 + . Our results show that PNA can serve for the identification and enumeration of monocytes in human peripheral blood.