BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Memento EPFL// BEGIN:VEVENT SUMMARY:Image Scanning Microscopy and Metal Induced Energy Transfer: Enhan cing Microscopy Resolution in All Directions DTSTART:20141014T110000 DTSTAMP:20261002T015017Z UID:3514ebdbdb9370f4a7794834346a9d7e5a5433c5a01aeddab2aca5f8 CATEGORIES:Conferences - Seminars DESCRIPTION:Prof. Jörg Enderlein\, Georg August University\, Göttingen ( D)\nBIOENGINEERING SEMINARAbstract:\nClassical fluorescence microscopy is limited in resolution by the wavelength of light (diffraction limit) restr icting lateral resolution to ca. 200 nm\, and axial resolution to ca. 500 nm (at typical excitation and emission wavelengths around 500 nm). However \, recent years have seen a tremendous development in high- and super-reso lution techniques of fluorescence microscopy\, pushing spatial resolution to its diffraction-dictated limits and much beyond. One of these technique s is Structured Illumination Microscopy (SIM). In SIM\, the sample is illu minated with a spatially modulated excitation intensity distribution\, and the emerging fluorescence is imaged with a conventional wide-field imagin g setup. By moving and rotating the excitation intensity distribution patt ern in different positions and orientations\, taking each time a wide-fiel d image\, a final fluorescence image is composed which has roughly double the resolution (laterally) of a conventional wide-field or a confocal lase r scanning image alone. A similar technique is Image Scanning Microscopy ( ISM). In ISM\, the focus of a conventional laser-scanning confocal microsc ope (LCSM) is scanned over the sample\, but instead of recording only the total fluorescence intensity for each scan position\, as done in conventio nal operation of an LCSM\, one records a small image of the illuminated re gion. The result is a four-dimensional stack of data: two dimensions refer to the lateral scan position\, and two dimensions to the pixel position o n the chip of the image-recording camera. This set of data can then be use d to obtain a super-resolved image with doubled resolution\, completely an alogously to what is achieved with SIM. However\, ISM is conceptually and technically much simpler\, suffers less from sample imperfections like ref ractive index variations\, and can easily be implemented into any existing LSCM.\nA second\, completely different approach which aims at achieving n anometer resolution along the optical axis is Metal Induced Energy Transfe r or MIET. When placing a fluorescent molecule close to a metal\, its fluo rescence properties change dramatically. In particular\, one observes a st rongly modified lifetime of its excited state (Purcell effect). This is du e to the efficient electromagnetic coupling of the excited state to surfac e plasmons in the metal\, which is similar to Förster Resonance Energy Tr ansfer (FRET)\, where the energy of an excited donor molecule is transferr ed into the excited state of an acceptor molecule. We call this effect met al-induced energy transfer or MIET. The MIET- coupling between an excited emitter and a metal film is strongly dependent on the emitter’s distance from the metal. We have used this effect for mapping the basal membrane o f live cells with an axial accuracy of ~3 nm. The method is easy to implem ent and does not require any change to a conventional fluorescence lifetim e microscope\; it can be applied to any biological system of interest\, an d is compatible with most other super-resolution microscopy techniques whi ch enhance the lateral resolution of imaging. Moreover\, it is even applic able to localizing individual molecules\, thus offering the prospect of us ing single-molecule localization microscopy for structural studies of biom olecules and biomolecular complexes.Bio:\n1981-86 Study of Physics at Ilya -Mechnikov-University Odessa\n1991 PhD in Physical Chemistry (Humboldt-Uni versity Berlin)\n1996-97 PostDoc at Los Alamos National Laboratory (USA)\n 1997-2000 Assistent Professor (C1) at University of Regensburg\n2000 Habil itation in Physical Chemistry (University of Regensburg)\n2001-2006 Heisen berg Fellow of the DFG at Forschungszentrum Jülich\n2007-2008 Professor f or Biophysical Chemistry at Eberhard-Karls-University Tübingen\nSince 200 8 Professor for Biophysics at Georg-August-University Göttingen LOCATION:SV1717a http://map.epfl.ch/?room=sv1717a STATUS:CONFIRMED END:VEVENT END:VCALENDAR