Scientists led by HHMI researcher Harald Hess have built on the super-resolution technique, PALM, to create iPALM. Interferometric photoactivated localization microscopy allows for 3D images instead of the normal 2D with PALM. Light from the sample is captured from both above and below, and the two light beams are sent to a beam splitter that directs them to three different cameras. The amount of light is used to calculate the vertical position of each fluorescent molecule in the sample. "In the end, we're able to get the position in all three directions of a molecule in less than 20 nanometers," or about 10 times the size of an average protein, says Hess in a story in Tech Review. As of now, it only works on fixed cells, but they hope to make it work for real-time imaging of live cells in the future.
PALM in 3D
Feb 10, 2009