Research

Single-molecule Microscopy

Single-molecule Localization Microscopy (SMLM) refers to a series of techniques which allow us to go beyond the diffraction limit, and reach resolutions of up to 20nm. Through these techniques, it is possible to study in detail biological structures, as well as the dynamics of molecules of interest through single-particle tracking (SPT). Much of my work in the field revolves around the development of microscopes able of performing such measurements on large scales, with the aim of understand how single-molecule motion correlates with biological phenomena. To this end I led the development of a large field-of-view 3D SMLM system in the Oxford Molecular Motors group, as well as a series of image processing and data analysis tools aimed at allowing us to combine information received from multiple cameras to gain a deeper understanding of the motility machinery powering the soil-bacterium Flavobacterium johnsoniae.

Microbial Motility

The world surrounding us is rich in swimming biological microorganisms. From the algae in the sea to the bacteria in the ponds and our body, going through the spermatozoa which allow fertilisation and life, microswimmers play a key role in many aspects of our life. A marvel of biological evolution for microorganisms has been the development of microbial motility. In fact, the majority of microorganisms share the ability to be able to swim thanks to whip-like appendages known as flagella (or cilia). Similarly to all other living organisms, microbes have developed ways to sense whether an environment is favourable for them and respond accordingly. For example, bacteria can sense a nutrient gradient if they are in one, and bias their motion to swim toward a food source or away from any toxic environment. The same principle is believed to be one of the main guidance mechanisms which lead the sperm to the egg and allow fertilisation, both in mammalians and not. Chemical gradients are not the only changes in the environment to which microorganisms can respond. It has been shown that algae can respond to illumination gradients (phototaxis), and both sperm and bacteria can respond to flow gradients (rheotaxis). Similarly, it is possible to observe responses from topographical gradients (topotaxis) and temperature gradients (thermotaxis). My PhD research focuseD on understanding how microorganisms respond to these different types of gradients, and how we could take advantage of these responses for bioengineering purposes through microfluidcs.