Phenotypic Characterization of Human Intermediate Monocytes

A full understanding of the immune system requires full characterization of the cells, and its subsets, which play a role in the process of host defense. The expression pattern of cell surface molecules serves as a major criterion for assigning cells into discrete subsets. The availability of monoclonal reagents, specific fluorescent probes and compatible instrumentation over the past years has led to identification and characterization of a great number of leukocyte subsets, including monocyte subsets, recently reviewed by Ziegler-Heitbrock and Hofer (1).