Separation of topological forms of plasmid DNA by anion-exchange HPLC: shifts in elution order of linear DNA.
We sought to establish a single anion-exchange HPLC method for the separation of linear, open circular and supercoiled plasmid topoisomers using purified topoisomeric forms of three plasmids (3.0, 5.5 and 7.6 kb). However, finding one condition proved elusive as the topoisomer elution order was determined to depend on salt gradient slope. The observed change in selectivity increased with plasmid size and was most pronounced for the linear form. Indeed, the elution order of the linear 7.6 kb plasmid was reversed relative to the supercoiled form. This observation may have implications for methods used in quality control of plasmid DNA.
Smith
Clara R
CR
BioPharmaceutical Product Development-US, GlaxoSmithKline, 5 Moore Drive, Research Triangle Park, NC 27709, USA.
DePrince
Randolph B
RB
Dackor
Jennifer
J
Weigl
Debra
D
Griffith
Jack
J
Persmark
Magnus
M
D000837:Anion Exchange Resins; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002852:Chromatography, Ion Exchange / Q000379:methods*; D004247:DNA / Q000302:isolation & purification*; D046529:Microscopy, Electron, Transmission; D010957:Plasmids / Q000302:isolation & purification*
D000837:Anion Exchange Resins; D004247:DNA