Researchers at Janelia Farm Research Campus of the Howard Hughes Medical Institute recently explained first details on the technology, the interferometric microscopy localization fotoaktivierte to call it - just iPALM. It enables the creation of three-dimensional images of structures within a cell with the highest resolution of an optical microscope.

iPALM complements the precursor technology to take a look at the third dimension. For PALM are fluorescent molecules that are switched on and off, so very small structures under a light microscope represent. If a cell investigated are only individual areas illuminated. A light mist is a relatively strongly scattered area in which bright points are located, which can individually control, for example, the position of proteins that involves fluorescent molecules were selected. A two-dimensional picture is supported by many of these snapshots.PALM To take a look at the third dimension to allow the researchers to use the interference measurement method, a technique of microscopically small areas in angles and distances can be calculated. Light from the fluorescent molecules in the sample is from the top and bottom and captured these two light beams then sent through a splitter, they are three different camera heads. The amount of light that each camera can then be used to adjust the vertical position of each fluorescent molecule within the sample to be determined. "At the end we can make the position in all three directions of a molecule in the range of less than 20 nanometers grasp," says Harald Hess, a researcher at the Janelia Farm Research Campus. This represents a ten times the size of an average protein.

John Sedat, professor of biochemistry and biophysics at the University of California, San Francisco, considers Hess' study of a masterpiece in the field of improving the resolution of light microscopes. A disadvantage of using such a high spatial resolution was in the field of biological imaging, however, that the cells previously killed and chemically fixed to be. A real-time detection was not possible.

The challenge in the field now there is progress in the field of spatial resolution with real-time images of living cells to combine. Gleb Shtengel, an expert in the field of research, admits that the inclusion of the spatial images takes too long to fast-running events to capture cell. "With an expansion of iPALM but it should be possible to slow processes in living cells can be observed. The plan we have."