ssDNA degradation along capillary electrophoresis process using a Tris buffer

Audrey Ric (1, 2, 3) , Varravaddheay Ong-Meang (1) , Verena Poinsot (1) , Nathalie Martins-Froment (4) , Fabien Chauvet (5) , Audrey Boutonnet (2) , Frédéric Ginot (2) , Vincent Ecochard (3) , Laurent Paquereau (3) , François Couderc (1, 6)

1 IMRCP - Interactions moléculaires et réactivité chimique et photochimique
2 Picometrics Technologies
3 PNP - Physiologie neurovégétative - PNV
4 ICT - Institut de Chimie de Toulouse
5 LGC - Laboratoire de Génie Chimique
6 IMRCP - BIBAC - IMRCP - Chimie analytique et interactions biomolécules - matière molle biomimétique

Tris-Acetate buffer is currently used in the selection and the characterization of ssDNA by capillary electrophoresis (CE). By applying high voltage, the migration of ionic species into the capillary generates a current that induces water electrolysis. This phenomenon is followed by the modification of the pH and the production of Tris derivatives. By injecting ten times by capillary electrophoresis ssDNA (50 nM), the whole oligonucleotide was degraded. In this paper, we will show that the Tris buffer in the running vials is modified along the electrophoretic process by electrochemical reactions. We also observed that the composition of the metal ions changes in the running buffer vials. This phenomenon, never described in CE, is important for fluorescent ssDNA analysis using Tris buffer. The oligonucleotides are degraded by electrochemically synthesized species (present in the running Tris vials) until it disappears, even if the separation buffer in the capillary is clean. To address these issues, we propose to use a sodium phosphate buffer that we demonstrate to be electrochemically inactive.

Mots clés: Biomolecules; Capillary electrophoresis; Oligonucleotides; Tris-Acetate buffer; ssDNA degradation

Domaines: Génie chimique; Génie des procédés

Audrey Ric, Varravaddheay Ong-Meang, Verena Poinsot, Nathalie Martins-Froment, Fabien Chauvet, et al.. ssDNA degradation along capillary electrophoresis process using a Tris buffer. Electrophoresis, 2017, 38 (12), pp.1624-1631. ⟨10.1002/elps.201600561⟩. ⟨hal-02134843⟩