Chromatography Forum

Hi,
I'm running biologigal samples on Resource Q anion exchange column + NaCl gradient from 300mM to 1500mM. Any tricks to clean the column from DNA between injections? My run time is 30 min already and I wouldn't like to increase it anymore.

thanks

Dear MK,

If I recall correctly, the resource Q is a porous strong anion exchanger. NaCl gradients, especially when relatively short, may allow DNA to remain on-column (Carryover). This is especially true for porous ion exchangers (as opposed to pellicular phases, such as the DNAPac columns).
In our hands, longer gradients minimize, but not eliminate this effect. Use of sodium perchlorate will also help minimize this carryover, as will elevated pH (~12) with either eluent. If the column will tolerate it, addition of solvent, such as acetonitrile may also help.

Cheers,
Jim Thayer
Dionex Corporation.