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The objective of this core is to provide technical, consultative, and equipment support for light, fluorescence and confocal microscopic studies needed to support the research activities of NINDS-funded investigators.

Multi-photon Confocal Microscope

The Center's Imaging Facility is equipped with a Zeiss LSM 510 NLO META system for state-of-the-art confocal microscopy, using a Zeiss Axiovert 100M inverted microscope. The illumination system incorporates one argon and two helium-neon lasers for single-photon excitation at 458, 488, 514, 543, and 633 nm, and a Coherent tunable titanium-sapphire laser for two-photon excitation (700-900 nm). The META spectral imaging system plus two conventional photomultiplier detectors offer simultaneous multi-channel color display of fluorescence. The 32-channel META spectral detector allows the separation of signals with extremely overlapping emission profiles, heretofore impossible using glass filters. For example, GFP and FITC may be separated with confidence. A transmitted light detector permits recording of brightfield and DIC images. User-friendly software features include 3D reconstruction, animation, time series, user-definable regions of interest for photobleaching and uncaging studies, multi-tracking to eliminate bleed through, emission fingerprinting, linear unmixing , quantification of colocalization , scale bar overlay, and a reuse button to duplicate system settings from a previously acquired image.

Two-photon scanning microscopy represents a powerful tool for investigating living cells and very thick specimens. Due to the non-linear characteristics of two-photon excitation, effective excitation takes place only in the focal spot of the objective lens. The highly localized excitation results in reduced photobleaching and phototoxicity, a distinct advantage for physiology experiments, including techniques like FRAP (fluorescence recovery after photobleaching ) and FRET (fluorescence resonant energy transfer). Live cell work is also facilitated by a temperature-controlled microincubator perfusion chamber (Harvard Apparatus), which may be mounted on the microscope stage.

Investigators interested in using the Confocal microscope can contact Howard Rees, PhD at 404/727-8043 or hrees@emory.edu.