title: End-labeled free-solution electrophoresis of DNA.
abstract: DNA is a free-draining polymer. This subtle but "unfortunate" property of highly charged polyelectrolytes makes it impossible to separate nucleic acids by free-flow electrophoresis. This is why one must typically use a sieving matrix, such as a gel or an entangled polymer solution, in order to obtain some electrophoretic size separation. An alternative approach consists of breaking the charge to friction balance of free-draining DNA molecules. This can be achieved by labeling the DNA with a large, uncharged molecule (essentially a hydrodynamic parachute, which we also call a drag-tag) prior to electrophoresis; the resulting methodology is called end-labeled free-solution electrophoresis (ELFSE). In this article, we review the development of ELFSE over the last decade. In particular, we examine the theoretical concepts used to predict the ultimate performance of ELFSE for single-stranded (ssDNA) sequencing, the experimental results showing that ELFSE can indeed overcome the free-draining issue raised above, and the technological advances that are needed to speed the development of competitive ELFSE-based sequencing and separation technologies. Finally, we also review the reverse process, called free-solution conjugate electrophoresis (FSCE), wherein uncharged polymers of different sizes can be analyzed using a short DNA molecule as an electrophoretic engine.
authors.affiliation: Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Meagher
authors.forename: Jong-In
authors.initials: JI
authors.lastname: Won
authors.forename: Laurette C
authors.initials: LC
authors.lastname: McCormick
authors.forename: Sorin
authors.initials: S
authors.lastname: Nedelcu
authors.forename: Martin M
authors.initials: MM
authors.lastname: Bertrand
authors.forename: Jordan L
authors.initials: JL
authors.lastname: Bertram
authors.forename: Guy
authors.initials: G
authors.lastname: Drouin
authors.forename: Annelise E
authors.initials: AE
authors.lastname: Barron
authors.forename: Gary W
authors.initials: GW
authors.lastname: Slater
mesh_terms: D004247:DNA / Q000737:chemistry / Q000302:isolation & purification*; D004586:Electrophoresis / Q000379:methods*; D008962:Models, Theoretical; D011506:Proteins / Q000737:chemistry; D012212:Rheology; D017422:Sequence Analysis, DNA; D012996:Solutions; D055672:Static Electricity
chemical_list: D011506:Proteins; D012996:Solutions; D004247:DNA