IDT changed the unit of measure for our custom DNA and RNA products from OD260 to nanomoles in December 2019. If you are comparing the minimum yield guarantee from your order confirmation or shopping cart with a previous sales order, the difference may be a result of this change.
This change was an acknowledgement of our customers’ tendency to use oligos in units of molar concentration or weight; by providing the minimum yield guarantees in nanomoles, the predictability of the quantity ordered improves, and conversion to nanomoles is no longer dependent on the sequence composition.
The new guarantees were determined following an extensive analysis of yield data from millions of oligonucleotides synthesized by IDT. This analysis considered complexity, purification, base type, and length. Using this data, we established yield guarantees that minimally impact the amount guaranteed while also maintaining or improving our manufacturing success rate and turnaround time of custom DNA and RNA oligo products.
While the minimum yield guarantee may be lower, IDT continues to provide the full synthesis yield for custom DNA and RNA products
You may also find the following article useful: Units of measure for oligo quantification.