- Certificate of analysis (COA)
- The laboratory report for one lot of a product. A useful certificate names the laboratory, the method for each test, the lot number and the date, then reports purity, identity, net peptide content and endotoxin. Read more →
- HPLC purity
- The share of peptide-related material in a vial that is the target sequence, measured by high-performance liquid chromatography with UV detection at 220 nm and reported as a percentage of total peak area. It does not include water or counter-ions. Read more →
- LC-MS identity
- Confirmation that the main peak is the intended peptide, made by comparing the measured mass from mass spectrometry with the mass calculated from the amino-acid sequence. Read more →
- Net peptide content
- The fraction of a lyophilized powder's weight that is peptide, measured by amino-acid analysis. The remainder is counter-ions such as acetate or trifluoroacetate and bound water. Labelling by net peptide means the milligrams on the vial are peptide. Read more →
- Endotoxin (LAL)
- Fragments of bacterial cell walls that survive sterilisation and provoke responses in cell-based and in-vivo work, measured by the limulus amebocyte lysate assay in endotoxin units per milligram. Pepstral lists lots below 0.5 EU/mg. Read more →
- Lyophilized
- Freeze-dried. The peptide solution is frozen and the water removed under vacuum, leaving a dry porous cake that is stable for years when sealed and kept cold. Read more →
- Reconstitution
- Adding water to a lyophilized vial to make a solution. Bacteriostatic water added slowly down the vial wall, then swirled, gives a known concentration: milligrams of peptide divided by millilitres of water. Read more →
- Bacteriostatic water
- Sterile water with 0.9% benzyl alcohol added as a preservative, used to reconstitute vials that will be drawn from more than once over the storage window. Read more →
- Lot number
- The identifier for one manufacturing and testing batch. The lot on the vial label must match the lot on the certificate in the COA library; if it does not, the certificate does not describe that vial. Read more →
- Solid-phase peptide synthesis (SPPS)
- The method by which research peptides are made: amino acids are added one at a time to a chain anchored on resin beads, then the finished peptide is cleaved from the resin and purified by preparative HPLC. Read more →
- Counter-ion
- The charged partner left bound to a peptide after purification, typically acetate or trifluoroacetate. It adds weight to the powder without adding peptide, which is why gross weight and net peptide content differ. Read more →
- Blend
- Two peptides co-lyophilized in one vial at a fixed ratio. The certificate reports each component separately. Blends remove the variable of preparing two solutions but fix the ratio. Read more →
- Research use only
- The sale condition for every product on this site: for in-vitro laboratory research by qualified personnel, not for human or animal use, diagnosis or treatment. Buyers confirm this at checkout. Read more →
- U-100 syringe unit
- One hundredth of a millilitre. A U-100 insulin syringe holds 100 units per mL, so a draw in millilitres times 100 is the number of units. Read more →
