Affiliation: | (1) Section Physics of Complex Systems, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands;(2) Present address: Departamento de Física de la Materia Condensada C-III, Universidad Autónoma de Madrid, 28049 Madrid, Spain |
Abstract: | We have imaged microtubules, essential structural elements of the cytoskeleton in eukaryotic cells, in physiological conditions by scanning force microscopy. We have achieved molecular resolution without the use of cross-linking and chemical fixation methods. With tip forces below 0.3 nN, protofilaments with ~6 nm separation could be clearly distinguished. Lattice defects in the microtubule wall were directly visible, including point defects and protofilament separations. Higher tip forces destroyed the top half of the microtubules, revealing the inner surface of the substrate-attached protofilaments. Monomers could be resolved on these inner surfaces.Abbreviations APTS (3-aminopropyl)triethoxysilane - DETA N1-[3-(trimethoxysilyl)propyl]diethylenetriamine - EM electron microscopy - MT microtubule - SFM scanning force microscopy |