title: PFA fixation enables artifact-free super-resolution imaging of the actin cytoskeleton and associated proteins.
abstract: Super-resolution microscopy (SRM) allows precise localization of proteins in cellular organelles and structures, including the actin cytoskeleton. Yet sample preparation protocols for SRM are rather anecdotal and still being optimized. Thus, SRM-based imaging of the actin cytoskeleton and associated proteins often remains challenging and poorly reproducible. Here, we show that proper paraformaldehyde (PFA)-based sample preparation preserves the architecture of the actin cytoskeleton almost as faithfully as gold-standard glutaraldehyde fixation. We show that this fixation is essential for proper immuno-based localization of actin-binding and actin-regulatory proteins involved in the formation of lamellipodia and ruffles, such as mDia1, WAVE2 and clathrin heavy chain, and provide detailed guidelines for the execution of our method. In summary, proper PFA-based sample preparation increases the multi-color possibilities and the reproducibility of SRM of the actin cytoskeleton and its associated proteins.
authors.affiliation: Division of Cell Biology I, The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam 1066 CX, The Netherlands.
authors.forename: Daniela
authors.initials: D
authors.lastname: Leyton-Puig
authors.affiliation: Division of Cell Biology I, The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam 1066 CX, The Netherlands.
authors.forename: Katarzyna M
authors.initials: KM
authors.lastname: Kedziora
authors.affiliation: Division of Molecular Genetics, The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam 1066 CX, The Netherlands.
authors.forename: Tadamoto
authors.initials: T
authors.lastname: Isogai
authors.affiliation: Division of Cell Biology I, The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam 1066 CX, The Netherlands.
authors.forename: Bram
authors.initials: B
authors.lastname: van den Broek
authors.affiliation: Division of Cell Biology I, The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam 1066 CX, The Netherlands.
authors.forename: Kees
authors.initials: K
authors.lastname: Jalink
authors.affiliation: Division of Molecular Genetics, The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam 1066 CX, The Netherlands m.innocenti@nki.nl.
authors.forename: Metello
authors.identifier: http://orcid.org/0000-0002-7455-2559
authors.initials: M
authors.lastname: Innocenti
keywords: Actin cytoskeleton; Fixation; Protein localization; Super-resolution microscopy (SRM); dSTORM