Atomic Force Microscopy of spermidine-induced DNA condensates on silicon surfaces

• Autor(a) principal: Carrasco, I.S.S.
• Data de Publicação: 2011
• Outros Autores: Bastos, F.M., Munford, M.L., Ramos, E.B., Rocha, M.S.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: https://doi.org/10.1016/j.msec.2011.09.008; http://www.locus.ufv.br/handle/123456789/18347
• topic: Atomic Force Microscopy; Polyelectrolytes; DNA condensation

In the present work, we show that oxidized silicon may be successfully used to image multivalent cation-induced DNA condensates under the Atomic Force Microscope (AFM). The images thus obtained are good enough, allowing us to distinguish between different condensate forms and to perform nanometer-sized measurements. Qualitative results previously obtained using mica as a substrate are recovered here. We additionally show that the interactions between the cation spermidine (the condensing agent) and the DNA molecules are not significantly disturbed by the silicon surface, since the phase behavior of an ensemble of DNA molecules deposited on the silicon substrate as a function of the cation concentration is very similar to that found in solution.