Figure 4

Analysis of neutrophil cytosol, plasma membranes, primary granules, and secondary granules by immunoblotting with monoclonal antibody 15H9. Neutrophil plasma membranes, cytosol, primary granules and secondary granules were prepared by nitrogen cavitation and differential centrifugation. Primary and secondary granules were disrupted and the membrane and contents were separated as described in the text. Cytosol (lane A), primary granule membranes (lane B), secondary granule membranes (lane C), plasma membranes (lane D), primary granules contents (lane E), and secondary granule contents (lane F) were analyzed by SDS-PAGE in a 13% gel under reducing conditions and were immunoblotted with antibody 15H9 (left panel) or NMS (right panel). Five micrograms of protein was added to each lane except for lane D in which 2 micrograms of protein was analyzed.