Research Product Quality and Testing Documentation Guide

Certificate of Analysis — a document issued by a testing laboratory that summarises analytical results for a specific product lot, including purity percentage, mass confirmation, and endotoxin levels.

High-Performance Liquid Chromatography — separates molecules in a sample based on polarity. Purity is reported as percentage of the target peak area relative to all detected peaks.

Mass Spectrometry — confirms the molecular weight of a compound to verify identity. ESI (Electrospray Ionization) is the most common soft ionization method used for peptides.

Mass-to-charge ratio — the unit used in mass spectrometry. The observed m/z value is compared against the theoretical value calculated from the compound's molecular formula.

Endotoxin Units per milligram — the measurement unit for bacterial endotoxin contamination. Lower is better; research-grade peptides typically target <5 EU/mg.

Freeze-dried — a preservation process that removes water under vacuum while the material is frozen, producing a stable powder that can be stored long-term without refrigeration.

Trifluoroacetate salt form — the default counter-ion form of most synthesized peptides. Some experiments require acetate form instead; this can usually be requested from the manufacturer.

The process of dissolving a lyophilized peptide powder in a suitable solvent (often sterile water, bacteriostatic water, or dilute acetic acid) to produce a research solution.