Are catalog sequences written from the N-terminus?

Yes. The residue order on these pages starts at the N-terminus. Confirm any modification of that end on the lot file, not from the product title.

Does the N-terminus decide purity?

No. It is a structural end. Purity is the chromatographic figure when the report includes one.

Glossary · 2026-09-24

Scientific lead: Alice Kay, Ph.D.

N-terminus of a peptide chain

The N-terminus is the end of a peptide chain that carries the free amine, unless a report states that the end is blocked or otherwise modified. Residue strings on this site are written from that end. Epithalon's catalog sequence starts at alanine. BPC-157's published string starts at glycine. Reversing a string would describe a different peptide.

The other end is the C-terminus. A blocked N-terminus changes the mass a laboratory should calculate. Do not add that modification unless the lot file states it. Sequence notation is in the sequence term and in the structure note. Research-use only.

Frequently asked questions

Are catalog sequences written from the N-terminus?: Yes. The residue order on these pages starts at the N-terminus. Confirm any modification of that end on the lot file, not from the product title.
Does the N-terminus decide purity?: No. It is a structural end. Purity is the chromatographic figure when the report includes one.

Research-use only. BlueNex Labs does not provide medical or veterinary advice. Confirm your institution’s policies before purchase.