Single cell cloning of Epstein-Barr virus transformed cells in 20-microliter hanging drops

A simple method for cloning EBV transformants from single cells in 20-microliter hanging drops is described. The hanging-drop method allows direct verification prior to the addition of irradiated feeder cells that clones will be established from single cells. The average efficiency of cloning from wells containing a single transformed cell was 74%, ranging from 60 to 95% in eight separate experiments.