Automated purification and quantification of oligonucleotides

We have developed automated methods for the trityl-on purification and quan tification of synthetic oligonucleotides. Oligonucleotide purification is b y solid-phase extraction cartridges using Amberchrom(R) CG-50 resin an an X YZ-axis robotic system. Quantification is by OD260nm using an online UV-vis ible spectrophotometer with sipper. The purification of 20 oligonucleotides requires 5 min of user set-up time, plus 20 min per sample of robot time F br a 15-25-mer at the 40 nmol scale of synthesis, the method gives a yield of 2.8 ODs from a load of 10.1 OD, i.e., a 28% average yield. Oligonucleoti des purified by this method have proven to be successful for primers for au tomated DNA sequencing.