Institut des Sciences Moléculaires d'Orsay




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Home > Research Teams > Biophysics and Biophotonic > Super-resolution microscopy and time-resolved imaging > Microscopies au delà de la limite de diffraction

From microscopy to nanoscopy

by Leveque-Fort Sandrine - 17 August 2015

We develop new instruments to overcome the diffraction limit by engineering fluorophores transitions or emission. Three new microscopes are being developed to achieve lateral or axial ultimate resolutions. The supercritical fluorescence emission provides absolute way to retrieve the axial position of the fluorophore regarding the coverslip that support the cell. Supercritical fluorescence microscope (SAF) allows to improve the axial resolution and simultaneously view the events in the first 150 nm and within the cell by introducing selective detection of the emission of fluorophores. We also work on the coupling of SAF detection with super-resolution techniques:
- The super-localization microscope (SMLM Single Molecule Localization Microscopy) decouples the detection of the fluorophores located in the same response function, by inducing fluorescence stochastically in order to individually localize single molecule. The association with SAF detection is currently performed as part of Nicolas Bourg thesis. The microscope DONALD (Direct Optical Nanoscopy with Axially Localized Detection) achieves an isotropic localization precision below 20 nm
- The STimulated Emission Depletion(STED) can achieve a lateral resolution of 40 nm by a selective depletion of fluorophores located at the periphery of the focusing zone, inducing a volume of study inherently reduced. The device was developed during the PhD Siddharth Sivankutty and coupling with SAF detection is in progress.
These new nanoscopy setups are applied to the study of neurobiological issues (for Alzheimer’s disease, Huntington) and for understanding the mechanisms of adhesion.

Single Molecule Localization Microscopy - SMLM / DONALD

-Supercritical Angle Fluorescence Microscopy - SAF

Stimulated Emission Depletion microscopy -STED