Single Particle Tracking

We are developing methods to carry out single particle tracking experiments in 3D. The major work that has been made was on the establishment of experimental systems, which can overcome the common problem of particles moving out of focus, thus giving a bad z resolution. We focus on fluorescence microscopy and imaging techniques to visualise dynamical processes in the cellular level. At this scale, high demands on the sensitivity and accuracy of the system are given which motivates us to combine sophisticated methods for well designed systems. For single particle tracking, we use not only conventional widefield microscopy, but currently also a confocal spinning disc microscope and a newly developed tracking microscope. With the spinning disc, our approach to 3d tracking is to take several image planes at a time. This image stacking includes the volume information of the sample. These stacks are then postprocessed to detect the movement of the particles in the volume. We wrote several programs for an accurate analysis and treatment of the obtained data. In contrary to the postprocessing method the newly developed microscope gives the xyz position online during measurement. The system also allows us to stays at the particles focus, so that a user can easily follow the focussed particle and its surroundings on the screen while the experiment is ongoing.