Harald Hess

Howard Hughes Medical Institute

Primary Section: 13, Physics
Secondary Section: 33, Applied Physical Sciences
Membership Type:
Member (elected 2018)


Harald Hess is an experimentalist who has contributed to several fields across physics and biology. After a PhD in Physics at Princeton in 1982, Harald Hess pursued hydrogen atom trapping and its Bose-Einstein condensation, BEC, at MIT as a postdoc. There he conceived of evaporative cooling as the means to achieve BEC which contributed to the 2001 Nobel Prize in Physics.  At Bell Labs he developed various low temperature scanning probe microscopes to visualize diverse physics phenomenon, such as vortices in superconductors, at Bell Labs. After 1997 he spent 8 years in industry developing advanced equipment for hard disk drive and semiconductor inspection and production. In 2005 he and a colleague, Eric Betzig, learned about photoactivatable fluorescent proteins and invented PALM (photo-activated localization microscopy) to reveal details of cell structure beyond the diffraction limit. It was built in a La Jolla condo, tested at the National Institute of Health and contributed to the 2014 Nobel Prize in Chemistry.  At Janelia Research Campus of Howard Hughes Medical Institute he extended PALM to a 3D super-resolution microscopy and is exploring its application for cell biology research.  There is also developing 3D electron microscopy techniques for volume imaging of cells and neural tissue.

Research Interests

Harald Hess’s research has the theme of both developing novel new forms of microscopy or refining existing microscopy technologies for the purpose of revealing new physical or biological attributes. This spans both 3D optical and 3D electron microscopy, EM. The goal is to develop the technology not in isolation but with biological needs in mind. One current focus is driven by the challenge of deciphering the neural connectivity of small brains such as the fly brain.  To this end, focused ion beam scanning electron microscopy has been reengineered to give a unique large volume capability with year-long imaging that is required of such samples.  This has become the imaging modality of choice for the Janelia FlyEM project. Furthermore, this technology has a much wider application space and takes EM from a traditional largely 2D view of a sample to a more complete 3D view of entire cells and tissues with a few nanometer resolution.  Finally, super-resolution fluorescent microscopies such as PALM are also combined with the electron microscopy technology to colorize protein locations on the 3D EM images.

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