Skip to Main Content


As noted here, every effort is made to maximize quality and yield in our unpurified oligos, and 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 is 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. 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 Oligo 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.