<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-source>NCI</n0:def-source><n0:def-definition>A selective cytochemical monocyte marker for alpha-naphthyl butyrate at pH 6.1. Alpha-naphthyl butyrate covers the external surface of the plasma membrane in monocytes and membrane-bounded intracellular organelles in lymphocytes.</n0:def-definition></n0:ComplexDefinition>