For easy ordering, checkout out the Life Technologies™ custom DNA oligos page

From Simple to Complex, We Have Your Bases Covered

  • The world’s highest capacity, resulting in prompt, reliable delivery
  • Computer-controlled synthesis system eliminates manual data transfer and re-entry data, allowing for accurate QC and shipping
  • quality control and validation of suppliers and raw materials includes 100% in-process trityl monitoring in real time and post-synthesis QC by capillary electrophoresis


Life Technologies™ Custom DNA oligos are synthetic oligonucleotides made according to your specifications and can be used in a variety of applications, from PCR and sequencing to probes for gene detection. Custom oligos are offered with standard deoxynucleotides, modified bases, and 5´- and 3´-modified nucleotides. Available modifications include fluorescent dyes, enzyme conjugates, and S-oligos for antisense studies. Invitrogen offers five standard synthesis scales and four purity options (Table 1).

Why do oligos sometimes require purification?

Oligos are made using a DNA synthesizer, a computer-controlled reagent delivery system. DNA is synthesized in the 3’ ⇒ 5’ direction, and each base addition is accomplished through a series of chemical reactions. But no chemical reaction is 100% efficient; during DNA synthesis, the maximum coupling efficiency obtainable is normally around 99%. Therefore, approximately 1% of the growing nucleotide chains fail to couple to a base in each round. In the case of a 30-mer oligo synthesis, the final product would also contain 29-mer failures, 28-mer failures, etc. For an oligo of this length, the percentage of full-length oligo is estimated to be between 74% and 54%, assuming a 99% or 98% reaction efficiency. The percentage of full-length oligo produced decreases as the length of the oligo increases.

The failure sequences inherent in the oligo synthesis process can compete with the full-length product in some applications; therefore, to help ensure success in downstream experiments, it may be necessary to purify the full-length oligo away from the failure sequences.

Table 1: Benefits of Custom DNA oligo purification methods

Purification method Description Benefit
DesaltOligos are processed through normal phase chromatography columns which removes salts but not failure sequencesA salt-free DNA solution, ready to use; suitable for many PCR and sequencing applications without further purification
CartridgeBased on reversed-phase chromatography; removes failure sequences from the completed synthesisProvides full-length sequences needed in some applications
HPLCReversed-phase high-performance liquid chromatography (HPLC) removes failure sequences or unincorporated label the same way as cartridge purificationGuarantees highly purified primer required in some applications (≥85% full-length)
PAGEMethod used to differentiate full-length product from failure sequences based on size and conformationProvides the highest percentage of full-length oligos (≥85%) required for certain demanding applications such as mutagenesis or adapter production


For easy ordering, checkout out the Life Technologies™ custom DNA oligos page