What Are Research Peptides? A Laboratory Primer

Peptides appear throughout biology, from hormones to signalling molecules, and they are a routine tool in laboratory science. This primer explains the basics for anyone new to the field.

What is a peptide?

A peptide is a short chain of amino acids joined by peptide bonds. There is no exact cut-off, but chains of up to roughly 50 amino acids are generally called peptides, while longer chains are called proteins. Oxytocin, a hormone of nine amino acids, and glutathione, a tripeptide of just three, are familiar examples.

How research peptides are made

Most research peptides are made by solid-phase peptide synthesis, a method developed by Bruce Merrifield in the 1960s. The chain is built one amino acid at a time while anchored to a solid resin, then cleaved off and purified, usually by preparative HPLC. The purified peptide is then freeze-dried into a stable powder.

Why purity matters

Each coupling step in synthesis is slightly less than perfect, so a crude product contains truncated and modified sequences alongside the target. These impurities can interfere with an experiment or produce misleading results. That is why purity is measured, reported and checked against a certificate of analysis.

Peptides, proteins and small molecules

• Peptides are short amino-acid chains, typically made by chemical synthesis.
• Proteins are longer chains, usually made in cells using recombinant methods.
• Small molecules are non-peptide compounds with a much lower molecular mass.

What does research grade mean?

Research grade indicates that a material is intended for laboratory use and is characterised for identity and purity. It is not a regulatory standard for medicines. Research peptides are not manufactured, tested or approved for use in people or animals.

All products on this site are supplied strictly for in-vitro laboratory research by qualified professionals.