Ultramicroscopy – a novel light sheet based imaging technique created by various research disciplines N. Ja ¨ hrling, S. Saghafi Ultramicroscopy (UM) is an interdisciplinary imaging technique allowing three dimensional reconstruction of up to cm-sized organs of animal models with mm resolution. Here, we present a review of technical and theoretical aspects of standard laser light sheet fluorescence microscopy. Fine morphological details in structures of animal models such as Drosophila melanogaster (fruit fly) and GFP-expressing mice, produced by UM are presented. Keywords: imaging; laser light sheet; ultramicroscopy; 3D image reconstruction; optical sectioning; fluorescence; green fluorescent proteins (GFP); animal models Ultramikroskopie – eine neue bildgebende Technologie auf Basis von „Laser Light-Sheets“, entwickelt in Zusammerarbeit mehrerer Forschungsdisziplinen. Die Ultramikroskopie (UM) ist ein interdisziplina ¨ res Verfahren. Diese Technik ermo ¨ glicht dreidimensionale Rekonstruktionen von bis zu cm-großen Organen von Tiermodellen mit einer Auflo ¨ sung im Mikrometerbereich. In diesem U ¨ bersichtsartikel werden technische und theoretische Aspekte der Standard-„Laser Light Sheet“-Technik erla ¨ utert. Mittels UM ko ¨ nnen morphologische Gewebedetails von Tiermodellen, wie etwa von Drosophila melanogaster (Fruchtfliege) und von GFP-exprimierenden transgenen Ma ¨ usen, dargestellt werden. Schlu ¨ sselwo ¨ rter: Bildgebung; Ultramikroskopie; 3D-Rekonstruktion; optisches Schneiden; Fluoreszenz; Gru ¨ n fluoreszierendes Protein (GFP); Tiermodelle Received August 2, 2011, accepted September 1, 2011 Ó Springer-Verlag 2011 1. Introduction The ultramicroscopy (UM) imaging technique allows three-dimen- sional reconstructions of cm-sized objects with micrometer resoluti- on. It is a prime example for an interdisciplinary research field (Dodt et al., 2007; Becker et al., 2008; Ermolayev, 2009; Ja ¨ hrling et al., 2009; Saghafi et al., 2010; Mu ¨ ller et al., 2010). The development of light sheet based technique requires interaction of fields such as biology, physics, chemistry, electronics and informatics (Fig. 1). UM bridges a gap between macroscopic imaging techniques, such as computer tomography, and microscopic imaging techniques, such as confocal microscopy. The technique of UM originated from a 100-years old idea of light sheet illumination presented by Sieden- topf and Zsigmondy (Siedentopf, Zsigmondy, 1903). They developed a light sheet microscope, called slit-ultramicroscope, which illuminat- ed gold particles with sunlight or the light of a mercury burner. Many different macroscopic technologies such as positron emis- sion tomography (PET), magnetic resonance imaging (MRI), X-ray computed tomography (CT), single photon emission computed to- mography (SPECT) have been developed to analyze the anatomy and function of organs (Borges, Casselman, 2010; Kang, 2010; Baker, 2010). These macroscopic procedures use ultrasound, gamma- or X-rays to analyze the internal organs of humans and animals. In general, image stacks of planes within the body are generated. Subsequently, from these data sets 3D reconstructions are computed. Being acknowledged as a non-invasive technology is the common advantage of these imaging techniques. However, resolving individ- ual cells in these techniques is a challenging task. Fig. 1. The interdisciplinary research fields in UM Ja ¨ hrling, Nina, Dipl.-Biol., Department of Bioelectronics, FKE, Vienna University of Technology, 1040 Vienna, Austria, and Sect. Biolelectronics, Center for Brain Research (MUW), 1090 Vienna, Austria, and Department of Neurobiology, University of Oldenburg, 26111 Oldenburg, Germany; Saghafi, Saiedeh, M.Sc., Ph.D., Department of Bioelectronics, FKE, Vienna University of Technology, 1040 Vienna, Austria, and Sect. Biolelectronics, Center for Brain Research (MUW), 1090 Vienna, Austria (E-mail: nina.jaehrling@tuwien.ac.at) 352 heft 10.2011 © Springer-Verlag e&i elektrotechnik und informationstechnik Elektrotechnik & Informationstechnik (2011) 128/10: 352–358. DOI 10.1007/s00502-011-0045-1 ORIGINALARBEITEN