Philippe Déjardin

Abstract A theory of the electrophoresis of DNA through gels with large interfiber spacing, such as dilute agarose, is presented. We assume that the DNA molecule moves along its axis through a “tube” in a neutral gel under the influence of the electric field. The tube is random except for possible bias due to the effects of the field. When the field is small, we easily recover the inverse‐length dependence of the mobility found previously by de Gennes and by Doi and Edwards. At higher fields, a new effect appears; the tube becomes oriented because the field biases the direction of the leading end of the chain as it moves to form an extension of the tube. This leads to an increase of the mobility with increasing field by adding a field‐dependent but length‐independent term to the mobility expression. In agreement with experiment, we find that the field effect can be important at fields as low as 1 V/cm and that the effect can seriously decrease the sensitivity of the mobility to chain length. We also examine the fluctuation of the migration distance, the degree of orientation induced by the field, and the transient effects occurring when the feld direction is rotated by a right angle.

Relationships between the molecular dimensions of polymers adsorbed on solid surfaces and the ’’hydrodynamic thickness’’ obtained by viscosimetry or flow rates through capillaries are derived by solving the corresponding Navier–Stokes equation. An exponential density distribution of polymer segments in the vicinity of the adsorbing interface was used. The theoretical results are discussed in connection with the experimental data of the literature.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReflectometry as a technique to study the adsorption of human fibrinogen at the silica/solution interfaceP. Schaaf, P. Dejardin, and A. SchmittCite this: Langmuir 1987, 3, 6, 1131–1135Publication Date (Print):November 1, 1987Publication History Published online1 May 2002Published inissue 1 November 1987https://pubs.acs.org/doi/10.1021/la00078a045https://doi.org/10.1021/la00078a045research-articleACS PublicationsRequest reuse permissionsArticle Views216Altmetric-Citations86LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts