Peptides are influenced by factors including temperature, moisture, light, pH, oxygen and repeated handling. The effect is peptide-dependent, so there is no one storage condition that works for all peptides.
What influences peptide stability?
A variety of factors can influence peptide stability.
Temperature: Heat can also speed up the rates of chemical reactions which cause peptide breakdown. Longer-term storage is often at lower temperatures.
Moisture: Water may be involved in some degradation reactions and may affect the stability of some dry peptide preparations.
pH: The nature of the peptide can be changed by changes in acidity or alkalinity and may also promote degradation under certain conditions.
Light and Oxygen Some peptides or components of some peptides may be sensitive to light and oxidation.
Time: Even under ideal conditions, the quality of peptides can vary over long periods.
Storage form: A peptide stored as a lyophilised powder may behave differently from the same peptide after it has been reconstituted in solution.
Stability of dry and dissolved peptides
A peptide’s stability can change significantly after reconstitution. In dry form, there is less available water for many chemical processes. Once dissolved, the peptide is exposed to its solvent, pH and other conditions that can influence its behaviour.
This is why storage recommendations for a lyophilised peptide may differ from those for a prepared peptide solution. Repeated freeze-thaw cycles can also affect some peptide solutions and should be avoided when they are known to reduce stability.
Stability vs purity
Stability and purity are not the same thing. Purity describes the proportion of the desired peptide in a sample, while stability describes how well that peptide remains unchanged over time.
A peptide may start out very pure, but during storage degradation products may slowly form. Hence, stability and purity can be considered in the evaluation of peptide quality.
Monitoring of peptide stability
Researchers can track peptide stability by taking samples at different time points and comparing them. HPLC can help to detect changes in the peptide profile and appearance of related impurities, while mass spectroscopy (MS) can help to identify changes in molecular mass.
Stability testing is usually performed in a defined environment such as a specific temperature, solvent, concentration and storage period. The results are meaningful within those specific conditions and should not automatically be applied to every peptide or storage situation.
When reviewing a peptide for research use, check the available Certificate of Analysis (CoA) and product information for storage recommendations, purity results and any available stability information.
Related terms: Degradation · Purity · Lyophilisation · Reconstitution · Aggregation · HPLC · Mass Spectrometry · Storage Conditions · Certificate of Analysis
All products supplied by Prime Peptides UK are intended for laboratory research use only and are not for human consumption.
Research Use Only. This glossary explains terminology used in published research. It is not medical advice and does not describe any product for human or animal use.