Stability and Storage

Do you assign your products expiration dates?

Oligonucleotides are chemically stable. An oligonucleotide stored lyophilized, or in proper buffer at -20°C, should remain stable for several years. We recommend a general shelf life of one (1) year for all oligonucleotides. Stored correctly, many will remain stable for many years. Each oligonucleotide is unique and we recommend our customers to perform stability studies, preferably in collaboration with us.

What are you recommendations for storage?

Our recommendation is to store our products at -20°C regardless if they are delivered lyophilized or in solution. Please note that we recommend you to keep the stock solution at ≥ 20 μM.

Why do you recommend storage at -20 °C and not -70 °C?

We recommend storage at -20 °C as we have seen that the lyophilization process is much faster at -70 °C. If you store the product in smaller volumes the concentration can change due to lyophilization. However, storage in -70 °C will not cause degradation of the oligonucleotide.

What type of buffer do you recommend for delivery?

There are two important points to consider when choosing buffer. Firstly, the pH should be above 6.5 in order to avoid depurination of dA and dG nucleotides. Therefore, just plain water should be avoided as its pH may well be as low as 5. Secondly, it is important to remove minute amounts of divalent ions, such as Mn, Cu. Zn, Mg, Fe etc., as these ions work efficiently as co-factors for a variety of nucleases. Removal of these ions completely inactivates the nucleases, and therefore we recommend having a small amount of EDTA present in the buffer. A buffer that fulfills both these points is 10 mM Tris-HCl, with either 0.1 mM or 1.0 mM EDTA.