ISOLATION OF THE PHAGOCYTIC COMPARTMENT FROM MACROPHAGES USING A PARAMAGNETIC, PARTICULATE LIGAND

Isolation of Fe receptor-dependent phagosomes from a macrophage cell line, J774 A.1, was accomplished using antibody-opsonized, paramagnetic beads. Following binding and ingestion of these beads, cells were homogenized in a standard membrane isolation buffer. Phagosomes containing the trapped paramagnetic beads were isolated by subjecting the whole cell homogenate to a magnetic field. The method is extremely simple and the preparation of an enriched phagosome fraction from a whole cell homogenate is rapid and highly selective. The method should provide useful starting material for investigators interested in cytoskeletal involvement in phagocytosis, in kinetic studies of ingestion, in phagosome-lysosome fusion, and in the ability of a particular ligand to initiate phagocytosis. © 1993 Academic Press. All rights reserved.