Unlike natural protein synthesis, peptides are synthesized from the C to N-terminus. At LifeTein, peptide synthesis is performed using PeptideSyn technology based on Fmoc or t-Boc chemistry to protect the alpha-amino group. The deprotection agent (piperidine for Fmoc, TFA for Boc) frees the alpha-amino group in preparation for coupling the next amino acid in the sequence. This reveals a new N-terminal amine to which the next amino acid may be activated by one of the several reagents, forming a peptide bond. When the synthesis is complete, peptides are cleaved from the resin and deprotected. Peptides are then precipitated, washed, and lyophilized.