Properties of blast cells in 'control' cultures of human blood lymphocytes. Preliminary note

Ficoll-Hypaque separated normal human peripheral blood lymphocytes undergo appreciable blastogenesis in RPMI 1640-pooled human serum or - autologous plasma. During the 1st week, granulated blasts with peroixdase activity and ultrastructural properties of granulocytes precursors appear. These cells, which appear to be relateed to CFC (colony-forming cells), contribute to the mitotic population in these unstimulated "control" cultures prior to 6 days.