Unaligned chromosomes and spindle abnormalities in NuMA-depleted cells. Depletion of NuMA was performed with siRNA2, as described in Fig. 1. Immunofluorescence of microtubules (green) and NuMA (red) was performed using monoclonal anti-NuMA, combined with a rabbit antibody against tubulin. DNA was stained with 4',6-diamidino-2-phenylindole (DAPI, blue). Arrows depict centrosomes that are slightly disconnected from the main body of the spindle in NuMA-depleted cells. The top row shows a cell treated with control RNA, for comparison. Micrographs were taken with a Leica TCS SP confocal microscope, equipped with a PlanApo 100x/1.4NA objective lens (Leica Microsystems). Bar, 5 μm.