title: Diamond cubic phase of monoolein and water as an amphiphilic matrix for electrophoresis of oligonucleotides.
abstract: We used a cubic liquid crystal formed by the nonionic monoglyceride monoolein and water as a porous matrix for the electrophoresis of oligonucleotides. The diamond cubic phase is thermodynamically stable when in contact with a water-rich phase, which we exploit to run the electrophoresis in the useful submarine mode. Oligonucleotides are separated according to size and secondary structure by migration through the space-filling aqueous nanometer pores of the regular liquid crystal, but the comparatively slow migration means the cubic phase will not be a replacement for the conventional DNA gels. However, our demonstration that the cubic phase can be used in submarine electrophoresis opens up the possibility for a new matrix for electrophoresis of amphiphilic molecules. From this perspective, the results on the oligonucleotides show that water-soluble particles of nanometer size, typical for the hydrophilic parts of membrane-bound proteins, may be a useful separation motif. A charged contamination in the commercial sample of monoolein, most likely oleic acid that arises from its hydrolysis, restricts useful buffer conditions to a pH below 5.6.
authors.affiliation: Department of Chemistry and Bioscience, Chalmers University of Technology, S412 96 Göteborg, Sweden.
authors.forename: Nils
authors.initials: N
authors.lastname: Carlsson
authors.forename: Ann-Sofie
authors.initials: AS
authors.lastname: Winge
authors.forename: Sven
authors.initials: S
authors.lastname: Engström
authors.forename: Björn
authors.initials: B
authors.lastname: Akerman
mesh_terms: D018130:Diamond / Q000737:chemistry*; D004587:Electrophoresis, Agar Gel / Q000379:methods*; D005989:Glycerides / Q000737:chemistry*; D009841:Oligonucleotides / Q000302:isolation & purification*; D014867:Water / Q000737:chemistry*
chemical_list: D005989:Glycerides; D009841:Oligonucleotides; D014867:Water; D018130:Diamond; C005953:monoolein