What is the shelf life of my oligonucleotides?

To gain a maximum shelf life for oligonucleotides, samples should generally be stored dehydrated at ≤ –15 °C in absence of light. Under the mentioned conditions, samples are stable for at least 6 months. In case of a longer storage period, oligos should be pretested for molecular integrity prior to experimental use. If stored frozen at –20 °C or –70 °C, it will remain stable for several months. Repeated freeze-thaw should be avoided, as this will denature the oligo. Moreover, the oligo stability in solution depends on the pH. Dissolving oligos into acidic solutions may result in oligo degradation. Therefore, avoid the use of distilled water, since solution pH may be as low as 4-5.

In addition to what above advised, we recommend that you minimize the exposure of modified oligonucleotides– especially those fluorescently labelled - to light, to avoid any bleaching effect.
Moreover, we recommend storing dye-labelled oligos highly concentrated and not in working dilutions, if you are not planning to use them within 24 hours. The higher the dilution factor, the faster the fluorescent activity fades away. Therefore, try to store highly concentrated aliquots frozen, thaw them only once, dilute them just before use and store the aliquots at 4 °C in the dark.