Imaging DNA molecules on mica surface by atomic force microscopy in air and in liquid.
DNA molecules immobilized on mica surface by various methods have been observed by atomic force microscopy both in air and in liquid. Divalent cations and 3-aminopropyltriethoxysilane (APTES) modified mica surface have been used to immobilize the DNA molecules. Optimal DNA and divalent cations concentration for AFM imaging are presented. Among the different methods of modifying mica surface with APTES, the water solution modifying method appears to get the best results. When using high DNA concentration for AFM imaging, DNA networks can be formed. A simple method to extend long DNA molecules is demonstrated. The optimal imaging conditions and AFM operating techniques are discussed. Different DNA immobilizing methods have been compared and evaluated.
Liu
Zhiguo
Z
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Graduate School of the Chinese Academy of Sciences, Changchun, Jilin, 130022 China.
Li
Zhuang
Z
Zhou
Hualan
H
Wei
Gang
G
Song
Yonghai
Y
Wang
Li
L
D000388:Air; D000538:Aluminum Silicates; D004247:DNA / Q000737:chemistry* / Q000648:ultrastructure; D018625:Microscopy, Atomic Force / Q000379:methods*; D010957:Plasmids; D011437:Propylamines; D012821:Silanes; D012996:Solutions; D014867:Water
D000538:Aluminum Silicates; D011437:Propylamines; D012821:Silanes; D012996:Solutions; D014867:Water; D004247:DNA; C477625:amino-propyl-triethoxysilane; C011934:mica