title: Helium Ion Microscopy (HIM) for the imaging of biological samples at sub-nanometer resolution.
abstract: Scanning Electron Microscopy (SEM) has long been the standard in imaging the sub-micrometer surface ultrastructure of both hard and soft materials. In the case of biological samples, it has provided great insights into their physical architecture. However, three of the fundamental challenges in the SEM imaging of soft materials are that of limited imaging resolution at high magnification, charging caused by the insulating properties of most biological samples and the loss of subtle surface features by heavy metal coating. These challenges have recently been overcome with the development of the Helium Ion Microscope (HIM), which boasts advances in charge reduction, minimized sample damage, high surface contrast without the need for metal coating, increased depth of field, and 5 angstrom imaging resolution. We demonstrate the advantages of HIM for imaging biological surfaces as well as compare and contrast the effects of sample preparation techniques and their consequences on sub-nanometer ultrastructure.
authors.affiliation: Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Joens
authors.affiliation: Ion Microscopy Innovation Center, Carl Zeiss Microscopy LLC, One Corporation Way, Peabody, MA 01960, USA.
authors.forename: Chuong
authors.initials: C
authors.lastname: Huynh
authors.affiliation: Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: James M
authors.initials: JM
authors.lastname: Kasuboski
authors.affiliation: Ion Microscopy Innovation Center, Carl Zeiss Microscopy LLC, One Corporation Way, Peabody, MA 01960, USA.
authors.forename: David
authors.initials: D
authors.lastname: Ferranti
authors.affiliation: Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Yury J
authors.initials: YJ
authors.lastname: Sigal
authors.affiliation: Center for Applied Geosciences, University Tübingen, Hoelderlinstr. 12, 72074 Tuebingen, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Zeitvogel
authors.affiliation: Center for Applied Geosciences, University Tübingen, Hoelderlinstr. 12, 72074 Tuebingen, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Obst
authors.affiliation: NMI Natural and Medical Sciences Institute, Markwiesenstr. 55, 72770 Reutlingen, Germany.
authors.forename: Claus J
authors.initials: CJ
authors.lastname: Burkhardt
authors.affiliation: Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Kevin P
authors.initials: KP
authors.lastname: Curran
authors.affiliation: Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Sreekanth H
authors.initials: SH
authors.lastname: Chalasani
authors.affiliation: Ion Microscopy Innovation Center, Carl Zeiss Microscopy LLC, One Corporation Way, Peabody, MA 01960, USA.
authors.forename: Lewis A
authors.initials: LA
authors.lastname: Stern
authors.affiliation: Ion Microscopy Innovation Center, Carl Zeiss Microscopy LLC, One Corporation Way, Peabody, MA 01960, USA.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Goetze
authors.affiliation: Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: James A J
authors.initials: JA
authors.lastname: Fitzpatrick
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000648:ultrastructure; D001419:Bacteria / Q000648:ultrastructure; D006367:HeLa Cells / Q000648:ultrastructure; D006371:Helium; D006801:Humans; D007477:Ions; D008853:Microscopy / Q000379:methods*; D008855:Microscopy, Electron, Scanning / Q000379:methods; D009348:Nematoda / Q000648:ultrastructure
chemical_list: D007477:Ions; D006371:Helium