Abstract

3D Single Particle Tracking: Following Mitochondria in Zebrafish Embryos

Don Lamb, Professor, Ludwig-Maximilians-University

By following a particle with high temporal and spatial resolution, we know its location with high precision and hence can determine its mobility, interaction partners etc., as it goes about performing its daily routine. For hundreds of years, single particle tracking (SPT) was used to follow the planets leading to the laws of gravitation. Today, it is possible to follow single viruses and even individual proteins in biological systems with nm-accuracy and ms-time resolution. In this lecture, I will discuss the basic principles of SPT. The first step is to follow the particle in two or three dimensions, which can be done using different microscopy methods. From these measurements, we can extract a trajectory of the particle as a function of time. From the trajectory, we can determine what type of diffusional behavior the molecule is undergoing. To exemplify what can be done via 3D SPT, I will discuss the principle of orbital tracking and show how we use it to follow the transport of mitochondria in living zebra-fish embryos. Thereby, we could detect transport processes that were not observable previously. In the 21st century, it is now possible to follow individual objects with nm-accuracy in three dimensions in real time in living organisms, which opens a whole new world for scientific investigation.