What is the synthesis scale and final yield?
Scale of synthesis refers to the amount of starting Controlled-Pore Glass (CPG) support-bound monomer used to initiate the DNA synthesis, not the amount of final material synthesized. This is the same for all manufacturers of synthetic DNA using standard phosphoramidite chemistry. When a 40 nmole scale synthesis is specified, approximately 40 nmoles of the first base is added to the DNA synthesizer. For an average 25-mer, at least 25% of this starting material will result in failure sequences. Hence it is not possible to produce 40 nmoles of full-length product from a 40 nmole scale synthesis. The losses occur during synthesis, post-synthetic processing, transfer of material, and quality control.
Final yield is the actual amount that we guarantee to deliver.
Please note that OD260 values are a measure of total nucleotides´ optical density. Hence, neither purity nor amount of ordered substance are transparently reflected. For simplification and exemplification reasons look at the following:
1 OD of the 20mer 5´CAT CGT ATT CGA TGC TAC GT 3´
translates into approximately 5 nmol.
1 OD of the 40mer 5´CAT CGT ATT CGA TGC TAC GT CAT CGT ATT CGA TGC TAC GT 3´
translates into approximately 2.5 nmol.
Therefore, a 1 OD guaranteed amount of delivered product can vary significantly, while metabion´s commitment to delivered yields in nmol does not allow for ambiguity in terms of what you expect and pay for.
For oligos of standard length (≤ 33 nucleotides) we guarantee a certain yield of DNA (OD260 applying to a 20-mer) to be delivered according to the respective scale of synthesis and mode of purification.
Our standard custom DNA portfolio features 4 synthesis scales with guaranteed yield expressed in ODs:
* = The yield guarantee is calculated for unmodified oligonucleotides (20mers).
0.02 µmol scale only available for oligos up to 33 bases.