title: Direct Observation of Wet Biological Samples by Graphene Liquid Cell Transmission Electron Microscopy.
abstract: Recent development of liquid phase transmission electron microscopy (TEM) enables the study of specimens in wet ambient conditions within a liquid cell; however, direct structural observation of biological samples in their native solution using TEM is challenging since low-mass biomaterials embedded in a thick liquid layer of the host cell demonstrate low contrast. Furthermore, the integrity of delicate wet samples is easily compromised during typical sample preparation and TEM imaging. To overcome these limitations, we introduce a graphene liquid cell (GLC) using multilayer graphene sheets to reliably encapsulate and preserve biological samples in a liquid for TEM observation. We achieve nanometer scale spatial resolution with high contrast using low-dose TEM at room temperature, and we use the GLC to directly observe the structure of influenza viruses in their native buffer solution at room temperature. The GLC is further extended to investigate whole cells in wet conditions using TEM. We also demonstrate the potential of the GLC for correlative studies by TEM and fluorescence light microscopy imaging.
authors.affiliation: †Department of Applied Physics, Harvard University, Cambridge, Massachusetts 02138, United States.|‡School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States.
authors.forename: Jungwon
authors.initials: J
authors.lastname: Park
authors.affiliation: §School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan 689-798, South Korea.
authors.forename: Hyesung
authors.initials: H
authors.lastname: Park
authors.affiliation: ∥The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
authors.forename: Peter
authors.initials: P
authors.lastname: Ercius
authors.affiliation: †Department of Applied Physics, Harvard University, Cambridge, Massachusetts 02138, United States.|‡School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States.
authors.forename: Adrian F
authors.initials: AF
authors.lastname: Pegoraro
authors.affiliation: ⊥Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, Massachusetts 02454, United States.
authors.forename: Chen
authors.initials: C
authors.lastname: Xu
authors.affiliation: #Department of Applied Chemistry, Hanyang University, Ansan 426-791, South Korea.|∇Department of Bionano Technology, Hanyang University, Ansan 426-791, South Korea.
authors.forename: Jin Woong
authors.initials: JW
authors.lastname: Kim
authors.forename: Sang Hoon
authors.initials: SH
authors.lastname: Han
authors.affiliation: †Department of Applied Physics, Harvard University, Cambridge, Massachusetts 02138, United States.|‡School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States.
authors.forename: David A
authors.initials: DA
authors.lastname: Weitz
mesh_terms: D000818:Animals; D002460:Cell Line; D004285:Dogs; D004847:Epithelial Cells / Q000648:ultrastructure*; D004867:Equipment Design; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D053122:Influenza A Virus, H3N2 Subtype / Q000648:ultrastructure*; D007251:Influenza, Human / Q000821:virology*; D061985:Madin Darby Canine Kidney Cells / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission / Q000295:instrumentation / Q000379:methods*; D012996:Solutions / Q000737:chemistry
chemical_list: D012996:Solutions; D006108:Graphite
keywords: Liquid phase TEM; bioimaging; epithelial cells; graphene liquid cell; influenza viruses; multilayer graphene