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Updated: Apr 17, 2026
Visualization of Recombinant DNA and Protein Complexes Using Atomic Force Microscopy
Published on: July 18, 2011
Study of DNA adsorption on mica surfaces using a surface force apparatus
Yajing Kan1, Qiyan Tan1, Gensheng Wu1
1Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, and School of Mechanical Engineering, Southeast University, Nanjing 211189, China.
Abstract:
We report our studies on the adsorption properties of double-stranded DNA molecules on mica surfaces in a confined environment using a surface force apparatus. Specifically, we studied the influence of cation species and concentrations on DNA adsorption properties. Our results indicated that divalent cations (Mg(2+) and Co(2+)) preferred to form uniform and moderately dense DNA layers on a mica substrate. By measuring the interactions between DNA-coated mica and bare mica in an aqueous solution, obvious adhesion was observed in a cobalt chloride solution, possibly due to the ion-correlation attraction between negatively charged DNA and the mica surface. Furthermore, the interaction differences that were observed with MgCl2 and CoCl2 solutions reveal that the specific adsorption behaviors of DNA molecules on a mica substrate were mediated by these two salts. Our results are helpful to elucidate the dynamics of DNA binding on a solid substrate.
