Micrographs of cultured peritoneal macrophages and bone marrow–derived colonies.

Left image, bright field; right image, fluorescence. (A) Peritoneal blood macrophages from heterozygous lys-EGFP not neo-deleted (+/ki) and neo-deleed (+/ki=neo D) mice 1 day after seeding in culture. (B) Macrophage colonies. Bone marrow cells prepared from a wild type (+/+) and from a lys-EGFP⁺/ki mouse were seeded in plasma clot cultures containing M-CSF. After 7 days, the plasma clots were partially dehydrated, and fluorescence pictures were taken of the colonies (right panels). Subsequently, the clots were fixed in methanol and stained with Diff-Quik, and the identical colonies were photographed under bright field (left panels).