You didn't indicate whether or not the macrophages are viable at the
time they become detached; however, it sounds to me that your macrophage
cultures are experiencing a growth factor deficiency. Macrophages
really need a constant supply of M-CSF to maintain good viability in
culture. Have you tried setting up feeder cultures (e.g., African green
monkey fibroblasts) or used fibroblast-conditioned medium with the
macrophages? Good luck.
Glenn
