SPPS in one paragraph
Solid-phase peptide synthesis builds a chain on a resin bead: protect, couple, deprotect, repeat. Cleavage releases the peptide, then HPLC purification isolates the main product. This is how most research catalog peptides are made.
Why long peptides are hard
Each coupling has incomplete yield. Errors accumulate with length. Sequences with difficult residues (e.g., hydrophobic stretches) aggregate on resin. That is why very long chains may shift to recombinant expression.
Purification drives price
Crude peptide is not research-ready. Prep HPLC, lyophilization, and analytical QC dominate cost. Modifications (PEG, fatty acids, cyclization, non-natural amino acids) add synthetic complexity.
Recombinant peptides and proteins
Insulin and many larger hormones are produced in cells. Chemistry and biology manufacturing routes have different impurity profiles—relevant when comparing “synthetic” vs “recombinant” on a COA narrative.
FAQ
What does SPPS stand for?+
Solid-Phase Peptide Synthesis—the dominant laboratory method for building custom peptide sequences on a solid support.