Plasmid DNA Purification
MACHEREY-NAGEL – 01/2008/ Rev. 04
11
Due to a specialized manufacturing process that is strictly controlled and monitored,
the
NucleoBond
®
Xtra
silica beads are uniform in diameter and contain particularly
large pores. These special properties allow optimized flow rates and sharp, well-
defined elution profiles.
NucleoBond
®
Xtra
can separate distinct nucleic acid species
from each other and from proteins, carbohydrates, and other unwanted cellular com-
ponents over an exceptionally broad range of salt concentrations (Figure 2).
All contaminants from proteins to RNA are washed from the column, the positive
charge of the resin is neutralized by a pH shift to slightly alkaline conditions, and pure
plasmid DNA is eluted in a high-salt elution buffer.
The purified nucleic acid products are suitable for use in the most demanding mo-
lecular biology applications, including transfection,
in vitro
transcription, automated or
manual sequencing, cloning, hybridization, and PCR.
Figure 2
Elution profile of NucleoBond
®
Xtra silica resin at pH 7.0
The more interactions a nucleic acid can form between the phosphate backbone and the
positively charged resin the later it is eluted with increasing salt concentration. Large nu-
cleic acids carry more charges than short ones, double stranded DNA more than single
stranded RNA.
