Purification

Every effort is made to maximize quality and yield in our unpurified oligos; they are suitable for most PCR and sequencing applications without further purification. When higher purity is required, we offer three types of purification.

Reverse-phase cartridge purification 

The trityl group at the 5' end of the molecule is left on at the completion of synthesis and is used as a hydrophobic "handle" to fish out the desired full-length chains. Failure sequences, lacking a trityl group, will then be removed and the oligo simultaneously desalted.

If you prefer to perform this type of purification yourself, we can provide a protocol for this procedure. In this case, YOU MUST SPECIFY THAT THE OLIGOS ARE TO BE RUN "TRITYL ON."

Reverse-phase HPLC purification 

Offered for DNA oligos <100 bases. High-performance liquid chromatography (HPLC) purification typically adds 3-5 business days to turnaround time. HPLC of modified DNA oligos may require an initial desalting/cartridge purification step before HPLC, so an additional charge may apply. 

Gel purification 

Gel purification typically adds one to two weeks to turnaround time. 

If you prefer to gel-purify the oligos yourself, a protocol is posted on our protocols page. Oligos >120 bases will contain significant amounts of organic salts that may cause smearing and/or poor band resolution. These oligos should be desalted before attempting gel purification.