Handbook of Size Exclusion Chromatography and Related ...

Endotoxin should also be removed from the plasmid fraction, especially in
clinical use. SEC could effectively remove endotoxin from the plasmid fraction for
use in a clinical trial (24).
From the partially purified plasmid, the separation of the supercoiled form
and the nicked or the relaxed form was achieved by SEC (20), although the
importance of the supercoiled form for clinical use is still under investigation.
5 OLIGONUCLEOTIDES
SEC has also been applied to oligonucleotides. However, there have not been
many applications of SEC to oligonucleotide separation because SEC generally
has a considerably lower resolution than other modes of high-performance liquid
chromatography such as reversed-phase and ion-exchange chromatography. One
example of the separation of oligonucleotide is shown in Fig. 8. A mixture of
oligodeoxyadenylic acids was separated on a TSKgel G2000SW two-column
system (each column 60 cm 7.5 mm ID). It is also possible to separate other
types of homogeneous oligonucleotides, such as oligodeoxythymidylic acid, and
heterogeneous oligonucleotides by SEC.
Figure 8 Separation of a mixture of oligodeoxyadenylic acids with chain lengths of 4, 8,
12, 16, and 20 nucleotides on a TSKgel G2000SW two-column system (each column
60 cm 7.5 mm ID) in 0.1 M phosphate buffer (pH 7.0) containing 0.1 M sodium chloride
and 1 mM EDTA at a flow rate of 1 mL/min. (Y Kato, unpublished data.)
© 2004 by Marcel Dekker, Inc.