Solubility of ZNA® and recommended stock solution concentrations
Due to their lower anionic nature (lower negative charge), compared to pure nucleic acids, ZNA® may be less soluble than other DNA/RNA-oligos in PCR grade water. The solubility of ZNA®s depends mainly on the ratio between nucleotides (anionic)/ spermines (cationic), pH and salt concentration. To avoid solubility issues, ZNA® oligos are delivered already dissolved by default..
If during your experiments you have to dry and re-dissolve your ZNA®, we recommend TE buffer pH 7.4. In case of solubility problems, we recommend adding 50 µl of 50 mM NH4 OH stepwise. Normally, the first 50 µl aliquot is already sufficient to bring a ZNA® oligo into solution. Standard stock concentration for ZNA®s is usually the same as for other PCR primers (100 µM is the delivered concentration). Working solutions of 10 µM should only be used for a short time and ideally prepared instantaneously prior to application.