2-chlorotrityl chloride resin loading

  1. Take the resin bottle out of fridge and warm up the resin at room temperature to avoid moisture deactivating the 2-chlorotrityl chloride resin.
  2. In barrier syringe weight the required amount of resin. Make sure the volume of the resin is less than 1/10 of the syringe volume.
  3. Weight the C-terminal Fmoc amino acid powder into the syringe. Use 2eq inexpensive amino acid, or use 1eq of expensive amino acid.
  4. Add DCM to achieve a concentration of 0.25M of amino acid to the syringe, followed by adding 4eq of DIPEA.
  5. Cap the syringe and tape the cap to avoid pressure pop up the cap.
  6. Shake the syringe at room temperature for 5~overnight according to the stability of the amino acid.
  7. To the loading reaction mixture, add 1/5 volume of methnol and shake for another hour.
  8. Wash the resin with DCM and add half volume of the syringe with 10% methnol in DCM and shake for another half hour.
  9. Wash the resin with DCM and DMF for 2X alternative rounds. Finally wash with DCM.
  10. Dry the resin in vacuum and test the loading.