Can you also tell me how do you generally purify your peptides so that I know what kind of impurities I am expecting? September 11, 2019 12:05 Updated The impurities are most likely salts, water, solvents, TFA, and deletion, truncation or incompletely deprotected sequences. Related articles What methods do you use to purify the peptide? What is peptide purity? What purification methods do you have in house? Could you please tell me the % purity that "crude" represents? In what direction are the peptides synthesized?