A, B and C: Three-dimensional reconstruction of a MWCNT-treated mitotic cell. Figure4A: This 3-dimension reconstruction was created from serial optical laser scanning confocal microscopy sections using immunofluorescence to identify centrosomes and microtubules while differential interference contrast was used to visualize aggregated MWCNT as previously described . Briefly, nanotubes of 10 nanometers or greater could be visualized by their interference with transmitted light using DIC imaging. Because the nanotubes block the light, the nanotubes produce a black image. The reconstructed image shows aggregated nanotubes which appear as irregular tangled black structures located inside the cell in association with the centrosomes (green), the microtubules (red) and the DNA (blue). In this cell, the one spindle pole, the doughnut shaped DNA arrangement and the disruption of microtubule attachments to clustered centrosome fragments into a monopolar spindle apparatus suggest major perturbations in cell division. The yellow arrows indicate nanotubes in association with mitotic spindle and the DNA. Figure 4B: The yellow arrows indicate the nanotubes (black) in association with the centrosomes (green) and the microtubules (red). Figure 4C: The yellow arrows indicate nanotubes (black) inside the centrosome structure (green).