Regensburg 2010 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 2: New Technologies

BP 2.1: Hauptvortrag

Montag, 22. März 2010, 10:15–10:45, H43

Probing Cellular Events with Single Quantum Dot Imaging — •Maxime Dahan — Ecole normale supérieure, Paris, France

In the past years, experiments on membrane molecules have demonstrated the potential of single quantum dot (QD) tracking to decipher the dynamics of complex events and to study biochemical reactions at the single molecule level, directly in live cells. Here I will discuss the principles, methods and challenges of single QD tracking. In particular, I will present our current effort to go beyond membrane dynamics and make QD imaging a standard imaging technique in cell biology. First, I will discuss how QDs can be internalized into live cells, how their colloidal properties affect their intracellular behavior and how QDs can be targeted to specific biomolecules or organelles. Next, I will show the results of recent experiments on the motion of molecular motors kinesin and myosin V in the cytoplasm of live cells. These experiments give access to important parameters such as the velocity, the processivity or stepping characteristics of the motor, directly in its cellular environment. Finally, I will present the challenges that need to be met to improve the properties of QDs as biological probes and the strategies that we are implementing to prepare small fonctional nanoparticles with controlled valency using peptide-coated QDs. Overall, the combination of tracking measurements, single-molecule counting methods and emerging high-resolution imaging techniques offer exciting possibilities to probe the composition, structure and dynamics of supramolecular assemblies in live cells.