Long oligo synthesis

  • Superior quality and yield
  • Unmatched DNA synthesis length, up to 200 bases. Longer oligo's on request.
  • RNA synthesis up to 100 bases
  • Very competitive pricing
  • Reliable service and fast turnaround times


Our B-pure Oligonucleotide Synthesis protocol produces custom synthesis of affordable, high-quality long oligos up to 200 bases. For oligonucleotides longer than 80 bases the B-pure protocol is the standard synthesis method. Oligo's longer then 200 bases can be synthesized on request after review of the sequence. 

Long oligos can be ordered in our webshop by entering your DNA sequences (up to 200 bases, longer oligo's on request) or RNA sequence (up to 100 bases).

Alternatively long oligos can be ordered by email. Download our excel orderform for ordering by email or use it to upload multiple sequences in our webshop.

Long oligos for medium and high-throughput applications oligos can be ordered in plates. No additional charge for orders containing more than 48 oligos per plate. More information about synthesis in plates.

Modifications can be incorporated in long oligos either during (direct) or after (indirect) synthesis.


You can choose from a wide variety of modifications. Please contact us for more information.

Coupling efficiency relates to the final amount of full length sequence after synthesis of your oligonucleotide.  Oligonucleotide synthesis is the step-wise addition of nucleotide residues to the 5'-site of the growing chain until the desired sequence is completed. Each addition of nucleotide residues is called a synthesis cycle. The coupling efficiency defines the efficiency of each synthesis cycle. 

By using the B-Pure synthesis protocol we can achieve an average coupling efficiency >99.5% for ideal sequences through an entire 200 base synthesis reaction. Longer oligo's can be ordered on request after review of the sequence. 

A coupling efficiency of 99% or 98% seems to be very good, but on closer examination the full-length yield is only half for a 40 mer! For a 200 mer this will result in a crude yield of less than 15%, which is not acceptable. As demonstrated in the figure below, the only way to synthesize longmers with an appreciable yield of full length material (>30%) is to have a coupling efficiency of more than 99.5%.



When an oligo increases in length, the total yield decreases. Furthermore, the likelihood of building loops, hairpins or other secondary structures during synthesis increases. This leads to a higher presence of deletions in the oligonucleotide sequence, which makes a PAGE purification strongly recommended for oligos over 50 bases. With PAGE purification you can reach a purity between 97% to 99.9% depending on oligo sequence and structure.

>More about purification