Thank you very much for your informative and helpful response!
Genscript did exactly what you mentioned. We are actually also waiting for an antibody from Biomatik to be delivered, so I hope they will send us a bit more.
I will definitely take this into consideration in the future.
Try Peptide 2.0 Inc or Bachem AG. Both are good. peptide2.com or bachem.com . Peptide 2.0 Inc is more popular for peptide synthesis. Bachem is a bigcompany and may offer other services.