Martin Schmidt

PhD defence by Martin Schmidt

On Friday 15 October 2021, Martin Schmidt will defend his PhD thesis "Optimization of localization-based microscopy methods with structured illumination".

Time: 13:00
Place: bldg. 341 aud. 23 and zoom:

Supervisor: Associate Professor Kim Mortensen
Co.Supervisor: Associate Professor Henrik Flyvbjerg
Co-supervisor: Associate Professor Jonas Nyvold Petersen

Members of assessment committee:
Associate Professor Emil Boye Kromann, DTU Health Tech
CNRS Research Director Sandrine Lévêque-Fort, Université Paris Saclay
Group Leader Jonas Ries, European Molecular Biology Laboratory, Heidelberg

Professor Niels B. Larsen, DTU Health Tech

Fluorescence microscopy is a valuable tool in the biosciences. It allows for live, non-invasive imaging and tracking of individual components of live cells, giving valuable insights into e.g., transport mechanisms in cells. However, the level of detail observed with light microscopy is limited by the spread of the observed light, an effect known as diffraction. Diffraction causes even single-nanometer sized molecules to image as spots with a width of several hundreds of nanometers, much larger than the molecule itself, making it difficult to pinpoint its exact location. By fitting a mathematical model to images of the particle, the position of a molecule can be determined with much greater precision than the inherent limits set by diffraction.

In this thesis, we developed an approach to determining the position of such particles by illuminating them with a structured illumination, e.g., a sinusoidal intensity profile. Under a structured illumination, the intensity with which the particle lights up depends on its position. By modelling the structured illumination, we can determine the position of such particles both from their position in an image, and from their intensities. We showed that this approach allowed us to determine the position of a particle based on its images with double the precision of conventional state-of-the-art methods.

We demonstrated the versatility of our approach by demonstrating that it works with any structured illumination, harmonic or not, 2D or 3D. This ensures that the approach is widely applicable, in the sense that it, in principle, can be implemented on any fluorescence microscopy modality in which structured illumination can be generated, opening up for many potential future implementations of the method.  



Fri 15 Oct 21
13:00 - 16:00


DTU Sundhedsteknologi


Bldg. 341, aud. 23 and zoom