title: Mica functionalization for imaging of DNA and protein-DNA complexes with atomic force microscopy.
abstract: Surface preparation is a key step for reliable and reproducible imaging of DNA and protein-DNA complexes with atomic force microscopy (AFM). This article describes the approaches for chemical functionalization of the mica surface. One approach utilizes 3-aminopropyl-trietoxy silane (APTES), enabling one to obtain a smooth surface termed AP-mica. This surface binds nucleic acids and nucleoprotein complexes in a wide range of ionic strengths, in the absence of divalent cations and in a broad range of pH. Another method utilizes aminopropyl silatrane (APS) to yield an APS-mica surface. The advantage of APS-mica compared with AP-mica is the ability to obtain reliable and reproducible time-lapse images in aqueous solutions. The chapter describes the methodologies for the preparation of AP-mica and APS-mica surfaces and the preparation of samples for AFM imaging. The protocol for synthesis and purification of APS is also provided. The applications are illustrated with a number of examples.
authors.affiliation: Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE, USA.
authors.forename: Luda S
authors.initials: LS
authors.lastname: Shlyakhtenko
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Gall
authors.forename: Yuri L
authors.initials: YL
authors.lastname: Lyubchenko
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000138:chemical synthesis / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000648:ultrastructure; D018625:Microscopy, Atomic Force / Q000379:methods*; D009707:Nucleosomes / Q000737:chemistry* / Q000648:ultrastructure; D017646:Organosilicon Compounds / Q000138:chemical synthesis / Q000737:chemistry; D010957:Plasmids / Q000737:chemistry / Q000648:ultrastructure; D011437:Propylamines; D012821:Silanes / Q000737:chemistry; D013499:Surface Properties; D059008:Time-Lapse Imaging
chemical_list: D000538:Aluminum Silicates; D019086:Bridged Bicyclo Compounds, Heterocyclic; D004268:DNA-Binding Proteins; D009707:Nucleosomes; D017646:Organosilicon Compounds; D011437:Propylamines; D012821:Silanes; C015503:silatrane; C477625:amino-propyl-triethoxysilane; C011934:mica