Reducing effects of particle adsorption to the air–water interface in cryo-EM

• Published in: Nature methods Vol. 15; no. 10; pp. 793 - 795
• Main Authors: Noble, Alex J., Wei, Hui, Dandey, Venkata P., Zhang, Zhening, Tan, Yong Zi, Potter, Clinton S., Carragher, Bridget
• Format: Journal Article
• Language: English
• Published: New York Nature Publishing Group US 01.10.2018; Nature Publishing Group
• Subjects: 631/1647/2258/1258/1259; 631/45/612; 631/57/2272; Adsorption; Air-water interface; Analysis; Apoferritin; Bioinformatics; Biological Microscopy; Biological Techniques; Biomedical and Life Sciences; Biomedical Engineering/Biotechnology; Brief Communication; Cryoelectron microscopy; Dwell time; Electron microscopy; Freezing; Hemagglutinins; Humidity; Insulin; Interfaces; Lectins; Life Sciences; Microscopy; Mud-water interfaces; Nanotechnology; Nanowires; Particulate matter; Proteins; Proteomics; Robots; Substrates; Thin films; Tomography; Water
• ISSN: 1548-7091; 1548-7105
• DOI: 10.1038/s41592-018-0139-3

Most protein particles prepared in vitreous ice for single-particle cryo-electron microscopy (cryo-EM) are adsorbed to air–water or substrate–water interfaces, which can cause the particles to adopt preferred orientations. By using a rapid plunge-freezing robot and nanowire grids, we were able to reduce some of the deleterious effects of the air–water interface by decreasing the dwell time of particles in thin liquid films. We demonstrated this by using single-particle cryo-EM and cryo-electron tomography (cryo-ET) to examine hemagglutinin, insulin receptor complex, and apoferritin. Reducing the length of time that protein particles spend on a sample grid prior to freezing mitigates deleterious effects caused by particle adsorption to the air–water interface in single-particle cryo-EM.