Long oligo synthesis
- Superior quality and yield
- Unmatched DNA synthesis length, up to 300 bases
- RNA synthesis up to 120 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 300 bases. For oligonucleotides longer than 80 bases the B-pure protocol is the standard synthesis method.
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 achieve an average coupling efficiency >99.5% through an entire 300 base synthesis reaction. 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 300 mer this will result in a crude yield of less than 5%, which is not acceptable. As demonstrated in the figure below, the only way to synthesize longmers up to 300 bases 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.