Structure of multipolar spindle in megakaryocytes.

Human megakaryocytes were obtained as previously described in Figure 1. Spindle immunostaining was performed with mouse antitubulin antibodies followed by incubation with TRITC-conjugated antimouse F(ab′)2 fragments. Endomitotic megakaryocytes with tetrapolar spindle, 8-polar spindle, and 16-polar spindle. Bar, 5 μm.