Fig. 2. Comparison of the protein composition of lysates of intact neutrophils (A), isolated MCPv (B) and isolated MCPa (C). Neutrophils (4x10⁸ cells) were allowed to phagocytose H37Rv or H37Ra for 60 minutes and were then homogenized and the phagosomes were isolated on 12% sucrose. Equivalent amounts of proteins from the whole lysates of neutrophils and isolated phagosomes were separated according to their isoelectric points on immobilized pH gradient 3-10 gels and then by standard SDS-PAGE. The letters a-c in (B) (MCPv gel) and d-g in (C) (MCPa gel) indicate as yet unidentified proteins (the kDa and pI values of these proteins are given in the text). The molecular weigh markers are indicated to the left in (A). The images shown are representative of silver stained gels from three separate experiments.