| AVS 55th International Symposium & Exhibition | |
| Biological, Organic, and Soft Materials Focus Topic | Tuesday Sessions |
| Session BO-TuP |
| Session: | Biological, Organic, and Soft Materials Focus Topic Poster Session |
| Presenter: | S. Weisse, University of Heidelberg, Germany |
| Authors: | S. Weisse, University of Heidelberg, Germany M. Heydt, University of Heidelberg, Germany A. Rosenhahn, University of Heidelberg, Germany M. Pettitt, The University of Birmingham, UK M. Callow, The University of Birmingham, UK J. Callow, The University of Birmingham, UK N. Heddergott, Technical University of Darmstadt, Germany M. Engstler, Technical University of Darmstadt, Germany M. Grunze, University of Heidelberg, Germany |
| Correspondent: | Click to Email |
Digital in-line holography is based on the original idea of D. Gabor’s “new microscopic principle”. Using this technique an interference pattern of both the so-called “source wave” and the “object wave” is recorded which contains three dimensional information about the observation volume. Real space information about the objects can be retrieved from these holograms through application of a reconstruction algorithm. One great advantage of a holographic instrument is that focusing can be done subsequently on a computer and three dimensional information about the object of interest can be obtained. Micro-fluidic experiments and tracking algae and bacteria, have shown that moving objects can be followed in three dimensions with remarkable accuracy and high time resolution. We present two applications for this technique: understanding biofouling and following the locomotion of pathogens. The exploration behavior of zoospores of the green algae Ulva is monitored to develop a deeper insight on how biofouling occurs on surfaces. Three surfaces (glass, a fluorinated surface and a PEG2000 surface) with different antifouling performances were investigated. For these three samples full 3D motion patterns were analyzed. In the bulk water, far from the surface, spores exhibit the same motility regardless of the investigated surfaces. In close proximity to the surface motility is significantly different. The interpretation of the exploration data leads to the previously unknown conclusion that these three surfaces are colonized via a different mechanism by zoospores. A second application involves examination of the locomotion of the blood parasite Trypanosoma brucei, the causative agent of African Sleeping sickness. The self-propulsion of Trypanosoma brucei in the bloodstream of a mammalian host is an essential part of its ability to withstand the mammalian immune system. To gain deeper insights into the pathogenesis of this blood parasite, a thermo-controllable flow channel setup was developed to allow the measurement of trypanosome trajectories under physiological conditions. Measurements are carried out in a buffer solution with dextran added to mimic the viscosity of mammalian blood and with and without flow to fully characterize motility. The obtained trajectories at different ambient properties are correlated with known effects in pathogenesis.