I would like to get some suggestions/feedback in regards to our
purification method for
"long" oligos (over 25bp). We have been having difficulty with low
yield using a reverse
phase cartridge (Waters Sep Pak C18). We synthesize the oligos leaving
the last DMT "on" and our protocol is as follows:
After cleavage and deprotection with concentrated NH4:
1. Rinse column with 100% Methanol
2. Rinse column with 0.1M Tea-Ac (Triethylamine / Acetic Acid pH 7.0)
3. Load Oligo onto column with 0.1M Tea-Ac
4. "Remove failures" with 11% Acetonitrile in 0.1M Tea-Ac
5. Remove DMTs with 1.5% TFA
6. Rinse with 0.1M Tea-Ac to neutralize TFA
7. Rinse with dH20 to desalt
8. Elute from column with ~ 1ml 40% Methanol, then lyophilized to
dryness.
Any suggestions or modifications to improve this protocol would be
greatly appreciated.
Thank you.
Mark
-- Mark O. Lively, Ph.D. Professor of Biochemistry Wake Forest University School of Medicine Medical Center Blvd. Winston-Salem, North Carolina 27157 Voice: 336-716-2969 Fax: 336-716-7200 email: mlively@wfubmc.edu