Laboratory of Optics and Biosciences

The Laboratory of Optics and Biosciences (LOB) is affiliated with the French Institute of Health and Medical Research (INSERM), the French National Centre for Scientific Research (CNRS), and Ecole Polytechnique. The Laboratory employs at a single site researchers with expertise in molecular and cellular biology, in optics and in femtosecond dynamics with the aim to favor the emergence of new concepts and tools, in particular for the understanding of protein dynamics and their functional organization inside cells and tissues

  • The laboratory is engaged in research on protein structural dynamics, in particular on proteins involved in the oxidative metabolism and in nitric-oxide- and oxygen-dependent signal transductions, on reaction and activation mechanisms of different enzymes as well as on the influence of natural or synthetic substances on the functioning of ion channels in the cell membrane. These research activities rely on the laboratory's expertise in the fields of protein engineering, molecular dynamics simulations and femtosecond lasers.
  • The structural dynamics associated with protein functioning includes molecular events on the femtosecond time scale. We use femtosecond pulses both to trigger a biochemical reaction and to follow the related structural and electronic changes. In order to obtain better insight and control of the relation between structural dynamics and protein function, we develop coherent femtosecond spectroscopy techniques, in particular in the mid-infrared, the spectral domain of molecular vibrations. In some cases, these techniques necessitate shaping of the femtosecond pulses. In the same spirit, protein folding is studied by new techniques involving ultraviolet time-resolved circular dichroism.
  • A major axis of our activity is to develop novel imaging approaches to probe cell activity inside intact tissue and at the single molecule level. In particular, we use femtosecond pulses for non-linear microscopy (two-photon-excited fluorescence, second- and third-harmonic generation, and coherent anti-Stokes Raman scattering), which have the unique ability to provide micrometer-scale 3D images from within complex media such as biological tissues. Our approaches rely on multimodal multiphoton microscopy, light-sheet imaging, femtosecond pulse-induced ablation, in vivo imaging of animal models, pulse shaping and the development of alternative fluorescent nanoparticles. Applications include the study of extracellular matrix remodeling, and of the biomechanics of embryo development. Another approach uses far-infrared radiation in the THz domain that is very sensitive to the ionic composition of biological media. We therefore develop a near-field THz microscope for the observation of excitable cells such as neurons.

The laboratory's researchers are involved in teaching at Ecole Polytechnique both in the Physics and the Biology Departments and in various graduate schools.
Contact person: Marie-Claire SCHANNE-KLEIN, research director




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