Testing method
Net peptide content
For laboratory research use only. Not for human consumption.
- What it measures
- How many milligrams of the named compound are in the vial.
- How it works
- The compound is quantified against a reference standard of known concentration, usually by HPLC peak area. Amino acid analysis is an alternative that hydrolyses the peptide and counts its residues.
- Sample
- The whole vial contents, dissolved to a known volume.
- Result reported as
- Milligrams of compound per vial, e.g. 21.33 mg for a 20 mg label.
- Limits
- Content and purity are different numbers. A vial can be 99% pure and hold less compound than the label states, or more. Lyophilised peptide also carries water and counter-ions, which add weight without adding compound.
- Standards
- USP General Chapter <1052> Biotechnology-Derived Articles — Amino Acid Analysis
- On our reports
- 21 of 23 published peptide reports state a measured quantity in milligrams.