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Mike HeilemannSuper-resolution fluorescence imaging with small organic fluorophores

Abstract :

Fluorescence microscopy has developed into an invaluable tool in biomedical research.
However, as any lens-based microscopy, the spatial resolution is limited to about 200 – 300 nm in the imaging plane and >500 nm along the optical axis, which is significantly larger than the biomolecular length scale.
In the recent past, a variety of fluorescence microscopy methods emerged that proved to bypass this fundamental limit in light microscopy. Among these are methods that employ photoactivatable or photoswitchable fluorescent probes in combination with nanometre-precision localization and image reconstruction (e.g. photoactivation-localization microscopy (PALM) and stochastic optical reconstruction microscopy (STORM); these methods can be summarized to localization-based super-resolution microscopy).
Even more recently, a more simplified method termed direct STORM (dSTORM) has been introduced that operates a large collection of conventional organic fluorophores (most of the Alexa, ATTO and Cy dyes) as photoswitches. Along with this increase in fluorophore flexibility, the advantage of the dSTORM concept is a simplified experimental scheme as well as live-cell compatibility. Moreover, the concept provides a concise control of photoswitching parameters and thus imaging speed, such that dynamic processes on much shorter time scales can be studied. This presentation will focus on the basic experimental principles of dSTORM, on the application of this concept to study cellular structures and dynamics, on novel strategies for specific labelling of biomolecules with organic fluorophores and on approaches to derive quantitative information on biomolecular organization and clustering at the molecular level.

Selected publications

Heilemann, M. (2010) Fluorescence microscopy beyond the diffraction limit. Journal of Biotechnology, doi: 10.1016/j.jbiotec2010.03.012.
Endesfelder, U.; van de Linde, S.; Wolter, S.; Sauer, M & Heilemann, M. (2010) Subdiffraction-Resolution Fluorescence Microscopy of Myosin-Actin Motility. ChemPhysChem, 11, 836-840.
Heilemann, M.; van de Linde, S.; Mukherjee, A. & Sauer, M. (2009) Super-resolution imaging with small organic fluorophores. Angewandte Chemie, 48, 6903-8.

Heilemann, M.; van de Linde, S.; Schüttpelz, M.; Kasper, R.; Seefeldt, B.; Mukherjee, A.; Tinnefeld, P. & Sauer, M. (2008) Subdiffraction-Resolution Fluorescence Imaging with Conventional Fluorescent Probes. Angew. Chemie, 47, 6172-6176.

Scientific focus :

• Development and application of advanced light microscopy techniques, in particular localization-based super-resolution imaging, multi-photon microscopy and fluorescence fluctuation imaging
• Organization, function and dynamics of biomolecules and cellular structures at the molecular level using super-resolution fluorescence imaging
• Photoswitchable and photoconvertible fluorescent probes for super-resolution live-cell imaging
• Single-molecule fluorescence methods to study biomolecular interactions in vitro and in vivo: single-molecule tracking, FRET spectroscopy/microscopy, alternating-laser excitation (ALEX) and fluorescence correlation spectroscopy (FCS)

Scientific Career

07/05 – 04/07 Postdoctoral Researcher at the University of Oxford (UK), Condensed Matter Physics and IRC for Bionanotechnology, Clarendon Laboratory (group of Dr. Achilles Kapanidis)

Since May 2007
Junior group leader at Bielefeld University, Physics Department and Bielefeld Institute for Biophysics and Nanoscience
Guest researcher at the University of Heidelberg, Bioquant Centre

January 2008
Young Investigators Award by the Federal Ministry of Education and Research (BMBF), funding of 1.44 Mio EUR for 5 years

Jean Baptiste Sibarita