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Marcel Leutenegger

Cette personne a quitté l’EPFL

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Publications associées (32)

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Single molecule detection on surfaces

Marcel Leutenegger

Monitoring biological relevant reactions on the single molecule level based on fluorescence spectroscopy techniques has become one of the most promising approaches for understanding a variety of phenomena in biophysics, biochemistry and life science. By ap ...

EPFL2007

Total internal reflection fluorescence correlation spectroscopy (TIR-FCS) with low background and high count-rate per molecule

Theo Lasser, Marcel Leutenegger, Kai Hassler, Ramachandra Rao

We designed a fluorescence correlation spectroscopy (FCS) system for measurements on surfaces. The system consists of an objective-type total internal reflection fluorescence (TIRF) microscopy setup, adapted to measure FCS. Here, the fluorescence exciting ...

2005

Object i.e. aneurysm, examining method for brain of patient, involves evaluating sequence of images by associating pixels with analysis image value depending on temporal changes of image values of pixels in specified frequency range

Theo Lasser, Marcel Leutenegger, Antonio Lopez, Erica Martin-Williams

NOVELTY - The method involves illuminating an object i.e. aneurysm, with measuring light with wavelengths ranging from 790 nanometer to 820 nanometer, and recording a sequence of images (21, 22) i.e. white light image, of the illuminated object. The sequen ...

2009

Detection efficiency in total internal reflection fluorescence microscopy

Theo Lasser, Marcel Leutenegger

We present a rapid and flexible framework for the accurate calculation of the detection efficiency of fluorescence emission in isotropic media as well as in the vicinity of dielectric or metallic interfaces. The framework accounts for the dipole characteri ...

2008

Multiple scattering in optical coherence tomography. I. Investigation and modeling

Theo Lasser, Marcel Leutenegger, Stéphane Bourquin, Boris Clément Karamata, Markus Laubscher

We present a new model of optical coherence tomography (OCT) taking into account multiple scattering. A theoretical analysis and experimental investigation reveals that in OCT, despite multiple scattering, the field backscattered from the sample is general ...

2005

High volume confinement in two-photon total-internal- reflection fluorescence correlation spectroscopy

Theo Lasser, Marcel Leutenegger, Iwan Märki

We report results on two-photon total-internal-reflection fluorescence correlation spectroscopy with radially polarized light. The combination of liquid crystal spatial light modulator, providing radial polarization, with ultrafast laser (picosecond Nd:GdV ...

AIP American Institute of Physics2009

Visible light optical coherence correlation spectroscopy

Heinrich Hofmann, Theo Lasser, Marcel Leutenegger, Arno Pino Bouwens, Daniel Pawel Szlag, Lionel André Maurizi, Stéphane Broillet

Optical coherence correlation spectroscopy (OCCS) allows studying kinetic processes at the single particle level using the backscattered light of nanoparticles. We extend the possibilities of this technique by increasing its signal-to-noise ratio by a fact ...

Optical Society of America2014

Dual-color total internal reflection fluorescence cross- correlation spectroscopy

Theo Lasser, Marcel Leutenegger

We present the development and first application of a novel dual-color total internal reflection (TIR) fluorescence system for single-molecule coincidence analysis and fluorescence cross-correlation spectroscopy (FCCS). As a performance analysis, we measur ...

SPIE Society of Photo-optical Instrumentation Engineers2006

Prism-based multicolor fluorescence correlation spectrometer

Theo Lasser, Marcel Leutenegger

We report the design and application of a prism-based detection system for fluorescence (cross) correlation spectroscopy. The system utilizes a single laser wavelength for the simultaneous excitation of several dyes of different emission spectra. Fluoresce ...

2006

Imaging of G protein-coupled receptors in solid-supported planar lipid membranes

Theo Lasser, Marcel Leutenegger

This contribution summarizes first some of our efforts in imaging G-protein-coupled receptor (GPCR) functional inserted into planar tethered lipid bilayer membranes (tBLMs) as a novel platform for biophysical studies. The authors introduced recently a nove ...

2009

Live-cell multiplane three-dimensional super-resolution optical fluctuation imaging

Theo Lasser, Françoise Gisou van der Goot Grunberg, Marcel Leutenegger, Noelia Laura Bocchio, Aurélien Godinat, Patrick Alain Sandoz, Azat Sharipov

Super-resolution optical fluctuation imaging (SOFI) provides an elegant way of overcoming the diffraction limit in all three spatial dimensions by computing higher-order cumulants of image sequences of blinking fluorophores acquired with a classical widefi ...

Nature Research2014

Fabrication of arrays of sub-wavelength nano-apertures in an optically thick gold layer on glass slides for optical studies

Theo Lasser, Benjamin Dwir, Patrik Willi Hoffmann, Marcel Leutenegger, Ivo Utke, Alexandre Perentes

We report on the fabrication of two-dimensional arrays of nano-optical apertures in gold layers by electron beam lithography (EBL) on a transparent glass substrate. 30 x 30 μ m(2) large arrays of high aspect ratio sub-wavelength cylinders (400 nm diameter ...

2005

See the Brain at Work—Intraoperative Laser Doppler Functional Brain Imaging

Michaël Unser, Dimitri Nestor Alice Van De Ville, Theo Lasser, Marcel Leutenegger, Antonio Lopez, Erica Martin-Williams

During open brain surgery we acquire perfusion images non-invasively using laser Doppler imaging. The regions of brain activity show a distinct signal in response to stimulation providing intraoperative functional brain maps of remarkably strong contrast. ...

2009

Triplet imaging of oxygen consumption during the contraction of a single smooth muscle cell (A7r5)

Dimitri Nestor Alice Van De Ville, Theo Lasser, Kai Johnsson, Marcel Leutenegger, Iwan Märki, Boris Hinz, Aurélie Formey de Saint Louvent, Thiemo Spielmann, Matthias Geissbühler

Triplet imaging is a novel optical technique that allows investigating oxy- gen metabolism at the single cell and the sub-cellular level. The method combines high temporal and spatial resolution, which are required for the monitoring of fast kinetics of ox ...

Springer Science+Business Media2012

Functional optical coherent imaging platform for medical application e.g. neurosurgery, has active camera unit that captures image of specific region of test subject after transmitting stimulus signals

Dimitri Nestor Alice Van De Ville, Theo Lasser, Marcel Leutenegger, Martin Villiger, Iwan Märki, Erica Martin-Williams

The present invention relates to a functional optical coherent imaging (fOCI) platform comprising at least one active camera unit (ACU) comprising a coherent and/or a partially coherent light source, and means for spectral filtering and imaging a selected ...

2010

Fast focus field calculations

Theo Lasser, Marcel Leutenegger, Ramachandra Rao

We present a fast calculation of the electromagnetic field near the focus of an objective with a high numerical aperture (NA). Instead of direct integration, the vectorial Debye diffraction integral is evaluated with the fast Fourier transform for calculat ...

2006

Mapping molecular statistics with balanced super-resolution optical fluctuation imaging (bSOFI)

Theo Lasser, Marcel Leutenegger, Noelia Laura Bocchio, Claudio Dellagiacoma, Corinne Berclaz

Super-resolution optical fluctuation imaging (SOFI) achieves 3D super-resolution by computing temporal cumulants or spatio-temporal cross-cumulants of stochastically blinking fluorophores. In contrast to localization microscopy, SOFI is compatible with wea ...

2012

Diffraction-unlimited imaging: from pretty pictures to hard numbers

Theo Lasser, Marcel Leutenegger

Diffraction-unlimited fluorescence imaging allows the visualization of intact, strongly heterogeneous systems at unprecedented levels of detail. Beyond the acquisition of detailed pictures, increasing efforts are now being focused on deriving quantitative ...

Springer Verlag2015

Combined Multi-Plane Tomographic Phase Retrieval and Stochastic Optical Fluctuation Imaging for 4D Cell Microscopy

Theo Lasser, Hilal Lashuel, Marcel Leutenegger, Emrah Bostan, Arno Pino Bouwens, Tomas Lukes, Adrien Charles-François Raymond Descloux, Anne-Laure Mahul Mellier

Super-resolution fluorescence microscopy provides unprecedented insight into cellular and subcellular structures. However, going beyond the diffraction barrier comes at a price since most far-field super-resolution imaging techniques trade temporal for spa ...

Nature Publishing Group2018

Zero-crossing approach to high-resolution reconstruction in frequency-domain optical-coherence tomography

Theo Lasser, Marcel Leutenegger, Chandra Sekhar Seelamantula, Arno Pino Bouwens

We address the problem of high-resolution reconstruction in frequency-domain optical-coherence tomography (FDOCT). The traditional method employed uses the inverse discrete Fourier transform, which is limited in resolution due to the Heisenberg uncertainty ...

2012