Subfractionation of human blood monocyte subsets with Percoll

Human monocytes can be separated into subsets of large and small cells by centrifugal elutriation. Small and large monocytes share many characteristics, but only small monocytes demonstrate enhanced cytotoxicity toward heterologous tumor cells. The small monocytes isolated by centrifugal elutriation are contaminated with lymphocytes that may hinder further characterization of this subpopulation. This study reports the application of Percoll in the purification of monocytes. The findings indicate that monocyte subsets isolated by centrifugal elutriation that differ in size are nevertheless equal in buoyant density.