Volume 25 Issue 5 July 2011

Clayton T. McKee, Vijay K. Raghunathan, Paul Russell and Christopher J. Murphy
School of Veterinary Medicine and School of Medicine, University of California, Davis, CA, USA
The importance of extracellular biophysical cues on basic cell behavior is rapidly changing our fundamental understanding of cell function. A better understanding of these basic cell functions necessitates the integration of multiple instrumental modalities. We have used a combined atomic force microscope and inverted fluorescent light microscope to better understand the morphology and mechanics of cellular behavior as a function of substratum topography. This combined instrument allows for  collection, as well as integration, of both mechanical and chemical information of adherent cells.

Alberto Diaspro,^1,2 Paolo Bianchini,¹ Francesca Cella-Zanacchi,¹ Benjamin Harke,¹ Michela Perrone,¹ Emiliano Ronzitti,¹ Silvia Galiani,^1,2 Jenu Chacko,^1,2 and Zeno Lavagnino.^1,2
1. IIT – Istituto Italiano di Tecnologia, Genoa, Italy. 2. LAMBS MicroSCoBio, Department of Physics, University of Genoa, Italy.
We report about coupling two-photon excitation (2PE) with two, comparatively young and successful optical methods specially realized for the improvement of resolution and 3D imaging of large samples, i.e. STED
(stimulated emission depletion) and SPI (selective plane illumination) microscopy. In the former case we aimed to get a better resolution for 2PE microscopy while for the latter we aimed to obtain better penetration in scattering samples by shifting the light sheet wavelengths to the red in the non-linear domain. We show results obtained by adapting a commercial STED-CW microscope to 2PE and by implementing a 2PE-SPIM homemade system. The implementation of these systems is demonstrated by the imaging of living Saccharomyces cervisiae cells.

David M. Pier, Derek S. Dauphin and Brendon S. Noble
School of Science, Technology and Health, University Campus Suffolk, Ipswich, UK
Autofluorescence typical of biological molecules limits the detection of common fluorophores such as DAPI, FITC and rhodamine. Using bone and cartilage as sample tissues we demonstrate that autofluorescent emission spectra overlap that of short wavelength fluorophores. At wavelengths above 650 nm autofluorescence emission intensity from both tissues is dramatically reduced, becoming undetectable in conditions that saturate the camera below 450 nm thus enhancing the resolution of epifluorescent imaging. Whilst long-wavelength fluorophores have been described for specialized imaging techniques, this study highlights the benefits of far-red fluorophores that are commonly available, and are compatible with most modern epifluorescent microscopes and routine staining protocols.

Petra Bele, Department of Physics E19, Technische Universität München, Garching, Germany
This article deals with a description and comparison of different electron detector systems for transmission electron microscopy. In the first part the important characteristic detector parameters are introduced and discussed. The second part deals with a direct comparison and contrast of three different electron detector media that are commonly used in electron microscopy. Detailed investigations were made on negative film, slow-scan CCD camera and imaging plates, showing that an almost complete noise correction of the image, leading to an almost ideal electron detector system, is only possible for the investigated imaging plate/scanner system.