Given that you are using an azide-oligo and DBCO-NHS ester for your conjugation, here is a recommended protocol to use:
- Dissolve your DBCO-NHS ester in DMSO, as concentrated as possible.
- Add the DMSO solution to the phalloidin amine. For the best conversion, the molar ratio of DBCO/phalloidin must be > 1.5.
- To the DMSO solution, add saturated NaHCO3 to adjust the reaction mixture to a pH > 8.5.
- Stir or vortex the reaction solution for 1-2 hours.
- Run HPLC or other purification methods to remove any decomposed DBCO
- The purified phalloidin-DBCO is ready for clicking with your oligo.