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Harald Hess | |
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| Born | September 12, 1955 |
| Nationality | American |
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| Known for | Photoactivated localization microscopy |
| Awards | Member of the National Academy of Sciences (2018) |
| Scientific career | |
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| Website | Hess Lab |
Harald Frederick Hess (born September 12, 1955) is an American physicist and Senior Group Leader at Howard Hughes Medical Institute's Janelia Research Campus, known for his work in scanning probe microscopy, light microscopy and electron microscopy. [1] [2]
Hess earned his BS degree in Physics from the University of Chicago in 1977 before pursuing further studies at Princeton University, where he obtained his PhD in Physics in 1982. [3]
As a postdoctoral researcher at MIT from 1982 until 1986, Hess focused his research on trapping hydrogen atoms and achieving Bose-Einstein condensation (BEC). During this time, he developed the concept of evaporative cooling as a means to achieve BEC, which was a significant contribution to the field and ultimately led to the awarding of the 2001 Nobel Prize in Physics. [4] [5]
Afterward, Hess joined Bell Labs as technical staff member. During his time there, he designed and developed a range of low-temperature scanning probe microscopes to visualize various physics phenomena, including vortices in superconductors.
After 1997, he spent eight years in industry at KLA-Tencor, where he focused on developing advanced equipment for the production and inspection of hard disk drives and semiconductors.
In 2005, he and his colleague Eric Betzig discovered photoactivatable fluorescent proteins and invented PALM (photoactivated localization microscopy), which enabled the visualization of cell structures beyond the diffraction limit. The PALM was constructed in a La Jolla condominium, [6] underwent testing at the National Institute of Health, and contributed to the awarding of the 2014 Nobel Prize in Chemistry. [7] [8]
At the Janelia Research Campus of the Howard Hughes Medical Institute, Hess further developed PALM into a 3D super-resolution microscopy technique and is currently exploring its potential applications for cell biology research. [9] [10] [11] Additionally, Hess is actively working on developing 3D electron microscopy techniques for volumetric imaging of cells and neural tissue. [12] [13] [14]
Overall, Hess's research centers on developing new forms of microscopy and refining existing technologies to uncover new physical or biological characteristics. [15]
Microscopy is the technical field of using microscopes to view objects and areas of objects that cannot be seen with the naked eye. There are three well-known branches of microscopy: optical, electron, and scanning probe microscopy, along with the emerging field of X-ray microscopy.
A microscope is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisible to the eye unless aided by a microscope.
A fluorescence microscope is an optical microscope that uses fluorescence instead of, or in addition to, scattering, reflection, and attenuation or absorption, to study the properties of organic or inorganic substances. "Fluorescence microscope" refers to any microscope that uses fluorescence to generate an image, whether it is a simple set up like an epifluorescence microscope or a more complicated design such as a confocal microscope, which uses optical sectioning to get better resolution of the fluorescence image.
Confocal microscopy, most frequently confocal laser scanning microscopy (CLSM) or laser scanning confocal microscopy (LSCM), is an optical imaging technique for increasing optical resolution and contrast of a micrograph by means of using a spatial pinhole to block out-of-focus light in image formation. Capturing multiple two-dimensional images at different depths in a sample enables the reconstruction of three-dimensional structures within an object. This technique is used extensively in the scientific and industrial communities and typical applications are in life sciences, semiconductor inspection and materials science.
Focused ion beam, also known as FIB, is a technique used particularly in the semiconductor industry, materials science and increasingly in the biological field for site-specific analysis, deposition, and ablation of materials. A FIB setup is a scientific instrument that resembles a scanning electron microscope (SEM). However, while the SEM uses a focused beam of electrons to image the sample in the chamber, a FIB setup uses a focused beam of ions instead. FIB can also be incorporated in a system with both electron and ion beam columns, allowing the same feature to be investigated using either of the beams. FIB should not be confused with using a beam of focused ions for direct write lithography. These are generally quite different systems where the material is modified by other mechanisms.
Stefan Walter Hell is a Romanian-German physicist and one of the directors of the Max Planck Institute for Multidisciplinary Sciences in Göttingen, and of the Max Planck Institute for Medical Research in Heidelberg, both of which are in Germany. He received the Nobel Prize in Chemistry in 2014 "for the development of super-resolved fluorescence microscopy", together with Eric Betzig and William Moerner.
Janelia Research Campus is a scientific research campus of the Howard Hughes Medical Institute that opened in October 2006. The campus is located in Loudoun County, Virginia, near the town of Ashburn. It is known for its scientific research and modern architecture. The current executive director of the laboratory is Ronald Vale, who is also a vice-president of HHMI. He succeeded Gerald M. Rubin in 2020. The campus was known as "Janelia Farm Research Campus" until 2014.
Jennifer Lippincott-Schwartz is a Senior Group Leader at Howard Hughes Medical Institute's Janelia Research Campus and a founding member of the Neuronal Cell Biology Program at Janelia. Previously, she was the Chief of the Section on Organelle Biology in the Cell Biology and Metabolism Program, in the Division of Intramural Research in the Eunice Kennedy Shriver National Institute of Child Health and Human Development at the National Institutes of Health from 1993 to 2016. Lippincott-Schwartz received her PhD from Johns Hopkins University, and performed post-doctoral training with Richard Klausner at the NICHD, NIH in Bethesda, Maryland.
Super-resolution microscopy is a series of techniques in optical microscopy that allow such images to have resolutions higher than those imposed by the diffraction limit, which is due to the diffraction of light. Super-resolution imaging techniques rely on the near-field or on the far-field. Among techniques that rely on the latter are those that improve the resolution only modestly beyond the diffraction-limit, such as confocal microscopy with closed pinhole or aided by computational methods such as deconvolution or detector-based pixel reassignment, the 4Pi microscope, and structured-illumination microscopy technologies such as SIM and SMI.
Fritiof Stig Sjöstrand was a Swedish physician and histologist born in Stockholm. He started his medical education at Karolinska Institutet in 1933, where he received his Ph.D. Karolinska Institutet in 1944. Sjöstrand worked as an assistant at the department of pharmacology, where he first had used polarization microscopy, he first heard about the new method of electron microscopy in 1938, within which he would become a pioneer. Manne Siegbahn at the Nobel Institute for Physics had planned to build an electron microscope in Sweden, and Sjöstrand got involved in the project to explore its use in medical research. The main challenge was to produce sufficiently thin samples, and Sjöstrand's method for producing ultrathin tissue samples was published in Nature in 1943. However, it seemed that research based on electron microscopy would be too time-consuming for a Ph.D. thesis, so his 1944 thesis was based on fluorescence spectroscopy. In 1947-1948, he received a scholarship to further study electron microscopy at Massachusetts Institute of Technology's Department of Biology. Back in Sweden, he received funding to build up an electron microscopy research laboratory. In 1959, Sjöstrand was both offered a position as professor of histology at Karolinska Institutet, and as professor at University of California, Los Angeles (UCLA). He chose UCLA, because conditions for research and funding were better there.
Photo-activated localization microscopy and stochastic optical reconstruction microscopy (STORM) are widefield fluorescence microscopy imaging methods that allow obtaining images with a resolution beyond the diffraction limit. The methods were proposed in 2006 in the wake of a general emergence of optical super-resolution microscopy methods, and were featured as Methods of the Year for 2008 by the Nature Methods journal. The development of PALM as a targeted biophysical imaging method was largely prompted by the discovery of new species and the engineering of mutants of fluorescent proteins displaying a controllable photochromism, such as photo-activatible GFP. However, the concomitant development of STORM, sharing the same fundamental principle, originally made use of paired cyanine dyes. One molecule of the pair, when excited near its absorption maximum, serves to reactivate the other molecule to the fluorescent state.
Live-cell imaging is the study of living cells using time-lapse microscopy. It is used by scientists to obtain a better understanding of biological function through the study of cellular dynamics. Live-cell imaging was pioneered in the first decade of the 21st century. One of the first time-lapse microcinematographic films of cells ever made was made by Julius Ries, showing the fertilization and development of the sea urchin egg. Since then, several microscopy methods have been developed to study living cells in greater detail with less effort. A newer type of imaging using quantum dots have been used, as they are shown to be more stable. The development of holotomographic microscopy has disregarded phototoxicity and other staining-derived disadvantages by implementing digital staining based on cells’ refractive index.
Robert Eric Betzig is an American physicist who works as a professor of physics and professor of molecular and cell biology at the University of California, Berkeley. He is also a senior fellow at the Janelia Farm Research Campus in Ashburn, Virginia.
Lattice light-sheet microscopy is a modified version of light sheet fluorescence microscopy that increases image acquisition speed while decreasing damage to cells caused by phototoxicity. This is achieved by using a structured light sheet to excite fluorescence in successive planes of a specimen, generating a time series of 3D images which can provide information about dynamic biological processes.
Michael Wesley Davidson was an American research scientist and microscopist. He used microscopes to create images of crystallized substances like DNA and hormones, and he contributed to Nobel Prize-honored research about the inner workings of cells. He is credited by 2014 Nobel Laureate Eric Betzig with teaching Betzig and fellow researcher Harald Hess about fluorescent proteins and providing the samples that led to the development of photoactivated localization microscopy (PALM), a super-resolution microscopy technique.
Na Ji is an American biophysicist and the Luis Alvarez Memorial Chair in Experimental Physics at UC Berkeley, where her work focuses on optical microscopy techniques for in vivo imaging and biophotonics. She has a joint appointment as faculty scientist at Lawrence Berkeley National Laboratory.
Suliana Manley is an American biophysicist. Her research focuses on the development of high-resolution optical instruments, and their application in studying the organization and dynamics of proteins. She is a professor at École Polytechnique Fédérale de Lausanne and heads the Laboratory of Experimental Biophysics.
Cryomicroscopy is a technique in which a microscope is equipped in such a fashion that the object intended to be inspected can be cooled to below room temperature. Technically, cryomicroscopy implies compatibility between a cryostat and a microscope. Most cryostats make use of a cryogenic fluid such as liquid helium or liquid nitrogen. There exists two common motivations for performing a cryomicroscopy. One is to improve upon the process of performing a standard microscopy. Cryogenic electron microscopy, for example, enables the studying of proteins with limited radiation damage. In this case, the protein structure may not change with temperature, but the cryogenic environment enables the improvement of the electron microscopy process. Another motivation for performing a cryomicroscopy is to apply the microscopy to a low-temperature phenomenon. A scanning tunnelling microscopy under a cryogenic environment, for example, allows for the studying of superconductivity, which does not exist at room temperature.
Structured illumination light sheet microscopy (SI-LSM) is an optical imaging technique used for achieving volumetric imaging with high temporal and spatial resolution in all three dimensions. It combines the ability of light sheet microscopy to maintain spatial resolution throughout relatively thick samples with the higher axial and spatial resolution characteristic of structured illumination microscopy. SI-LSM can achieve lateral resolution below 100 nm in biological samples hundreds of micrometers thick.
Catherine G Galbraith is an American scientist and an Associate Professor of Biomedical Engineering at OHSU and Discovery Engine Investigator at Knight Cancer Institute, known for her work in cell mobility and cell migration as well as super-resolution microscopy. Together with James Galbraith, she heads the Galbraith Lab.
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