What is it about?

We developed and manufactured modules for sample agitation in the cryochambers of the most widely used automated freeze substitution systems, AFS(1) and AFS2 (Leica Microsystems), and demonstrated that automated processing with sample agitation saves time, increases flexibility with respect to sample requirements and protocols, and produces data of at least as good quality as other approaches.

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Why is it important?

Conventional chemical fixation and processing at room temperature lead to artifacts due to shrinkage, extraction, aggregation and redistribution of biological material. High-pressure freezing followed by freeze substitution avoids such artifacts. Since freeze substitution is notoriously slow, it is important to accelerate the substitution process by agitation. We tested magnetic force-driven agitation modules that offer the possibility of straightforward refitting of automated freeze substitution systems (AFS) that are currently in use because it does not interfere with the electronics and construction of the AFS itself. Given the widespread distribution of AFS in EM labs world-wide, we conclude, that the acceleration of FS with agitation modules, offers a cost-effective way to generate cryopreparations in much shorter times, at high quality.


Writing this article was a great pleasure as it brought together the developers of the agitation modules and co-authors of other EM labs for testing of the modules for various needs. We hope that the application of the agitation modules might increase the use of cryopreparation methods in the overall sample preparation for light- and electron microscopy, also correlated with and analytical techniques.

Siegfried Reipert
University of Vienna

Read the Original

This page is a summary of: Agitation Modules: Flexible Means to Accelerate Automated Freeze Substitution, Journal of Histochemistry & Cytochemistry, July 2018, SAGE Publications, DOI: 10.1369/0022155418786698.
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