title: Potential Artifacts in Sample Preparation Methods Used for Imaging Amyloid Oligomers and Protofibrils due to Surface-Mediated Fibril Formation.
abstract: Accurate imaging of nanometer-sized structures and morphologies is essential to characterizing amyloid species formed at various stages of amyloid aggregation. In this article, we examine the effect of different drying procedures on the final morphology of surface-mediated fibrils formed during the incubation period, which may then be mistaken as oligomers or protofibrils intentionally formed in solution for a particular study. Atomic force microscopy results show that some artifacts, such as globules, flakelike structures, and even micrometer-long fibrils, can be produced under various drying conditions. We also demonstrate that one can prevent drying artifacts by using an appropriate spin-coating procedure to dry amyloid samples. This procedure can bypass the wetting/dewetting transition of the liquid layer during the drying process and preserve the structure of interest on the substrate without generating drying artifacts.
authors.affiliation: Department of Chemistry, University of Pennsylvania , 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, United States.
authors.forename: Yi-Chih
authors.identifier: 0000-0002-6498-215X
authors.initials: YC
authors.lastname: Lin
authors.affiliation: Department of Chemistry, University of Wisconsin at Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States.
authors.forename: Milton H
authors.initials: MH
authors.lastname: Repollet-Pedrosa
authors.affiliation: Department of Chemistry, University of Pennsylvania , 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, United States.
authors.forename: John J
authors.initials: JJ
authors.lastname: Ferrie
authors.affiliation: Department of Chemistry, University of Pennsylvania , 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, United States.
authors.forename: E James
authors.initials: EJ
authors.lastname: Petersson
authors.affiliation: Department of Chemistry, University of Pennsylvania , 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, United States.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Fakhraai
mesh_terms: D000682:Amyloid / Q000648:ultrastructure*; D016229:Amyloid beta-Peptides / Q000648:ultrastructure*; D016477:Artifacts; D003890:Desiccation / Q000379:methods; D018625:Microscopy, Atomic Force / Q000379:methods*; D012996:Solutions; D013499:Surface Properties
chemical_list: D000682:Amyloid; D016229:Amyloid beta-Peptides; D012996:Solutions