Science 320, 1332–1336 (2008)

Credit: L. SCHERMELLEH & P. CARLTON

Cellular structures as small as 100 nanometres can be viewed in three-dimensional (3D) colour images thanks to a technique that doubles the resolution of fluorescence light microscopy.

The technique illuminates samples with three interfering beams of laser light, enabling it to circumvent the resolution limit of traditional light microscopy that is set by the wavelengths of visible light.

John Sedat at the University of California, San Francisco, and Heinrich Leonhardt at the Ludwig Maximilian University of Munich, Germany, and their colleagues developed this '3D structured illumination microscopy' and used it to construct the first 3D colour image of a nuclear pore and its environment. The picture (above) shows a mouse nucleus with condensed chromosomes (red), surrounded by a fibrous network called the nuclear lamina (green).