hplc of plasmids/small DNA fragments?
bthomas at gmm.gen.emory.edu
Tue Oct 31 14:20:29 EST 1995
Waters Corp. has a fast anion exchanger that is useful for analysis and
purification of DNA: its called Gen-Pak FAX. Other companies have
these as well, example Perkin Elmer. In general they use 2 to 3 micron
nonporous particles. These give much better resolution than the various
porous ion exchangers that are marketed for DNA analysis and
purification. The Gen-Pak has a higher capacity than most and is
probably better suited for purification than its competitors.
Methodology has been developed for separation of DNA on nonporous
divinylbenzene reversed phase columns. Resolution looks very good but I
haven't tried it myself. The advantage here seems to be that the DNA
comes out in much lower salt than you have to deal with when using anion
Using anion exchange (or reversed phase), you can count on separations
taking 10-30 minutes with resolution equal to agarose gels for DNA from
<20 to around 10 kb. Usable separations can be gotten from 10-30 kb.
You can also get good separations between double-strand and single
strand, supercoiled and nicked circles etc.
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