(B) Confocal microscopy images of fixed nuclei assembled for 120 min in mock depleted (mock) and Nup50 depleted (∆Nup50) Xenopus egg extracts supplemented with either buffer or recombinant Nup50. In the left column, membranes were pre-labelled with DiIC18 (1,1'-Dioctadecyl-3,3,3',3'-Tetramethylindocarbocyanine Perchlorate, red) and chromatin was stained with DAPI (4′,6-Diamidin-2-phenylindol, blue). Three right columns show the immunofluorescence staining for Nup50 (green) and, NPCs (mAB414, red) on the chromatin (DAPI). Scale bars: 10 µm. 