Plenary 2.3

8/31 4:00 - 6:00, Memorial Auditorium

Light Sheet Based Fluorescence Microscopes (LSFM, SPIM, DSLM) Reduce Phototoxic Effects by Several Orders of Magnitude

Ernst H. K. Stelzer

Professor of Biophysics, European Molecular Biology Laboratory (EMBL), Heidelberg.

Most biochemical compounds absorb light and suffer photo-toxic degradation inducing malfunction or death of a specimen. This is particularly dramatic in conventional/confocal fluorescence micro-scopy. Even though a single plane is observed, the entire specimen is illuminated. Recording stacks of images along the optical axis thus illuminates entire specimens once for each plane. Hence cells are illuminated 10-20 and fish embryos even 100-300 times more often than observed. This can be avoided by re-arranging the optics. We use light sheets, which are fed into the specimen from the side to overlap with the focal plane of a wide-field fluorescence microscope. Optical sectioning and no photo-toxic damage outside a small volume around the focal plane are intrinsic properties. Light sheet-based fluorescence microscopes (LSFM) use modern cameras with a signal to noise ratio that is at least thirty times better than in a confocal microscope. LSFM can be combined with essentially every contrast and specimen manipulation tool. Recently, LSFM were used to record zebrafish (Da-nio rerio) development in vivo and in toto from the 32-cell stage until late neurulation with sub-cellular resolution and 60-90sec sampling.

Ernst H. K. StelzerErnst Stelzer started working on confocal fluorescence microscopy in 1983, developed the 4Pi microscope during 1990-1992 and since 1993 worked on various orthogonal and multi-lens detection schemes (e.g. confocal theta fluorescence microscopy). Recently, he invented and applied the novel azimuthally arranged light-sheet-based fluorescence mi-croscopes (SPIM, DSLM). Dr. Stelzer authored and co-authored about 200 papers and three books. Several of his patents secure commercially available instruments, most promi-nently the Carl Zeiss LSM series. Other contributions include the optical tweezers based Photonic Force Microscope, commercialized by JPK (Berlin, Germany) and novel ap-proaches to laser cutting devices. In his talks he currently discusses: a) the importance of actively addressing “Three-dimensional Cell Biology and Biophysics” and b) light sheet based fluorescence microscopy (LSFM) and its applications in the life sciences. Ernst Stelzer is the scientific group leader for Light Microscopy in EMBL's Cell Biology and Biophysics Unit in Heidelberg, a principal investigator at the CEF in Frankfurt am Main and a Professor for Biophysics at Frankfurt's Goethe University.