August 31, 2023: Prof. Elizabeth Stroupe & Behrouz Ghazi Esfahani, Florida State University.

The cryo-EM sample from Dante’s inferno: one solution to the air-water interface challenge
Specimen preparation remains a bottleneck for cryo-EM, despite recent advancements that are addressing the challenges. Traditional plunge-freeze methods often result in complications like aggregation or preferred orientations at the air/water interface. Alternative methods lack a universal solution, requiring multiple techniques for challenging samples, however there are many reports that show these approaches can be used separately or as a hybrid method to overcome the challenges. In this talk we will present our observations that both sulfite reductase and a chimeric methionine tRNA synthetase undergo the denaturation/aggregation process of during the plunge-freezing on Chameleon. In combination with a high-CMC detergent, the specimen is protected from falling apart. We get the best plunging result by using the Chameleon in presence of this reagent - neither has sufficient protection on its own.