How stable is my probe once I have resuspended it?
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 a sterile solution (e.g. water, biological buffer) is used as diluent, the re-suspended the probe will be stable at 20 °C for several days to weeks, at 4 °C for about a month. If stored frozen at –20 °C or –70 °C, it will remain stable for several months.
For correct storing and best performance of your probe, we recommend the following:
- Avoid repeated freeze-thaw, as this will denature the probe;
- Avoid the use of distilled water as a diluent, since its pH may be as low as 4–5. The probe stability in solution depends on the pH. Dissolving probes into acidic solutions may result in oligo degradation. Therefore, use purified distilled water;
- Minimize the exposure of fluorescent probes to light, to avoid any bleaching effect;
- Store probes 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 you use the probe and store the aliquots at 4 °C in the dark.