Abstract text (incl. figure legends and references)

The yeast Saccharomyces cerevisiae is a well-established model organism for cell biological research. The availability of large mutant collections, the fast growth and easy handling make it ideally suited for systematic large-scale analyses. However, sample preparation of yeast cells for transmission electron microscopy (TEM) of thin sections is a time-consuming process, limiting the feasibility of large-scale screening for yeast mutants with altered ultrastructure by TEM. Here, we present two approaches to reduce the time necessary for conducting a systematic TEM-based screen of yeast deletion mutants. First, we apply pooling of ten different strains to increase the amount of mutants that can be simultaneously screened for a specific ultrastructural phenotype. In a proof of concept experiment, we were able to reliably identify samples containing mutants with altered mitochondrial ultrastructure. Second, we employ a microwave-assisted protocol to accelerate sample preparation. This reduces the time requirement for chemical fixation and Epon embedding to less than 24 hours, making it ideally suited when dealing with a high number of samples. Taken together, both approaches facilitate large-scale screening of yeast deletion mutants.