This course will cover the process of rapid freezing, fracturing, coating and imaging of a variety of samples.
Details
Contact Us to Schedule
Targeted Participants
Individuals who are new to the field of cryo SEM, or desire a technical refresher to maintain current skills, or just those that want to see and learn all of the possibilities of the technology.
Format
Lecture, demonstration and hands-on practice, as well as round table discussion. Participants are encouraged to bring their own samples, if possible.
Main Curriculum
- Theory and overview of cryo SEM
- Mounting and adhering
- Freezing, loading and fracturing
- Insitu coating
- Operation of SEM
- Cryo face-off Leica UC 7 Crion
- Specific techniques of Cryo SEM imaging
Instruments Available
- Hitachi S3500 SEM
- PP3010 Cryo Preparation System
- Leica UC7 Ultramicrotome
- Leica Crion Cryomicrotome
- COXEM SEM EM-30N
Enrollment Note
Registration will be limited to a maximum of 15 participants. EMS will provide samples to those who prefer not to bring their own.
Cryo SEM
Many types of samples such as ice cream, pastes, paints, and gels do not lend themselves to routine SEM sample preparation methods such as critical point drying or freeze drying due to the morphologic changes caused by desiccation. To avoid these artifacts it is necessary to image the hydrated or natural state. This requires that the sample be rapidly frozen, to reduce ice crystal damage, and fractured to reveal their physical / functional sub-surface morphology. These samples are applied to the stub, immersed in liquid nitrogen slush loaded into the Cryo fracturing and coating chamber, and finally the SEM. This final preparation takes place in a high vacuum environment thus minimizing the possibility of frost contamination. Within the SEM, while viewing, the sample temperature can be maintained at -130° or warmed slightly to facilitate sublimation of the surface. The selection of accelerating voltage (kV), for surface detail, and spot size for resolution and charging are critical and will be covered in detail.
Parameters such as working distance which affects depth of field (Dfi) and resolution, plus tilt and raster rotate will be examined for proper image collection.