Jurkat cells were trapped in the microchambers of a novel disk-shaped cell separation device and stained with Cellstain. Approximately 90% of the cells were living. Single cells were isolated with a branching microchannel after rotation at 4500 rpm for 30 s, demonstrating that a living single cell could be trapped in the microchambers. (C) 2011, The Society for Biotechnology, Japan. All rights reserved.