Phagocytosis of apoptotic cells by human macrophages: analysis by multiparameter flow cytometry.

Background: Phagocytic removal of apoptotic cells is an important regulatory event in development, tissue homoeostasis, and inflammation. There are several methodologic problems with most in vitro studies of the molecular mechanisms of apoptotic cell phagocytosis. First, cell loss occurs during rigorous washing of adherent macrophages required to ensure removal of noningested particles.