During my thesis, the concept of super-resolution microscopy by photoactivated localization was invented. In this technique, a conventional widefield microscope is used to acquire fluorescence imaging of a biological sample. However, unlike conventional fluorescence microscope, in PALM, the highlighting of proteins of interest is achieved by PTFPs that can be photoactivated, so that only a small fraction of fluorescent molecules can be observed at a time.

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The stochastic activation of those individual molecules makes that they are spatially distinguishable and can be precisely localized... with a much better accuracy than that obtained by conventional microscopy where all the molecules emit their fluorescence simultaneously, limiting the achievable optical resolution to ~200-300 nm.

Observing single fluorescent molecules with very sensitive cameras, thus, allows the reconstruction of a composite image that does not suffer from the physical law of far-field diffraction-limited imaging. This type of localization microscopy, invented in 2006 and awarded by the Nobel Prize in Chemistry 2014 permits to obtain ~20-nm resolution images but requires the use of adapted PTFPs.