EQUIPMENT: SEM/EDX

(Carl Zeiss Microscopy GmbH, Germany)

With its variable pressure modes of operation, ZEISS SIGMA VP field emission scanning electron microscope (FE-SEM) allows imaging of non-conducting samples. The system offers many advantages for applications in environmental analysis and (in combination with cryo equipment, see below) enables true surface imaging of nanoparticles, bacteria, cells, etc.

Our FE-SEM system is equiped with EDS Quantax XFlash 6l60 Detector (Bruker Nano GmbH, Germany) which is suitable for analysis of nanoparticles and (micro)biological  samples.

Financial support by the German Research Foundation (DFG, "Forschungsgroßgeräte") is gratefully acknowledged.

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(GATAN, Inc.)

The combination of Cryo system GATAN ALTO 2500 with FE-SEM allows imaging and analysis of hydrated and (micro)biological samples. Nitrogen gas chilled with liquid nitrogen is used cooling of cryo chamber and FE-SEM.

Financial support by the German Research Foundation (DFG, "Forschungsgroßgeräte") is gratefully acknowledged.

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(GATAN, Inc.)

This cryo system is a semi-automated plunge freezing instrument used for the preparation of frozen hydrated specimens (colloids, microorganisms) on grids for cryo FE-SEM analysis. The specimen grid, clamped between the tines of plunging tweezers and containing generally 3 micro liters of the specimen suspension, is blotted to produce a thin, aqueous film. It is then plunged into a temperature monitored ethane bath and the specimen suspension is rapidly frozen as non-crystalline ice. A liquid nitrogen workstation maintains the temperature of the liquid ethane vessel just above the freezing point of liquid ethane. The specimen grid is then transferred to the ALTO 2500 Cryo system for FE-SEM analysis.

Financial support by the German Research Foundation (DFG, "Forschungsgroßgeräte") is gratefully acknowledged.

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