Glossary

The words on a product page, a COA and a quote.

Short definitions; the numbers are the ones sourced in the product fact tables and guides.

Sections

Identity

What the material is: names, forms, CAS numbers and molecular weights.

GHK-CuCopper Tripeptide-1, prezatide copperWhat is GHK-Cu?: The copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine. The neutral 1:1 complex is C14H22CuN6O4, 401.91 g/mol; CAS 89030-95-5 identifies the copper complex.
GHKTripeptide-1What is GHK?: The tripeptide Gly-His-Lys without copper: C14H24N6O4, 340.38 g/mol, CAS 49557-75-7. It is the ligand of GHK-Cu and a different material from it.
AHK-CuCopper Tripeptide-3What is AHK-Cu?: The copper(II) complex of L-alanyl-L-histidyl-L-lysine — GHK-Cu with alanine in place of glycine. The neutral 1:1 complex is 415.94 g/mol (calculated from AHK, 354.41 g/mol).
1:1 and 2:1 complexWhat is the difference between 1:1 and 2:1 GHK-Cu?: A 1:1 complex holds one GHK per copper (401.91 g/mol); a 2:1 complex holds two (742.3 g/mol). In solution near neutral pH GHK and copper(II) form the 1:1 complex.
CAS numberWhy do GHK and GHK-Cu have different CAS numbers?: A CAS number identifies one substance. 89030-95-5 is the copper complex and 49557-75-7 the peptide without copper, so a GHK-Cu document with 49557-75-7 names the wrong material.

Copper data

The copper lines of a copper-peptide COA and how to read them.

Cu²⁺ : peptide molar ratioWhat is the Cu²⁺ : peptide ratio?: Copper ions per peptide molecule, calculated as (copper % ÷ 63.546) ÷ (peptide % ÷ peptide molecular weight). It is about 1.0 for a 1:1 complex and about 0.5 for a 2:1 complex.
Theoretical copper contentHow much copper is in pure GHK-Cu?: 15.81 % of the pure 1:1 complex (63.546 ÷ 401.91) and 8.56 % of the 2:1 form. A real batch also holds acetate and water, so its as-is copper result is lower.
d–d bandabout 606 nm for GHK-CuWhat is the d–d band of GHK-Cu?: The broad visible absorption of copper(II) bound in the peptide, at about 605–606 nm near neutral pH. It is why GHK-Cu looks blue; with imidazole bound it moves to about 565 nm.
As-is resultWhat does 'as-is' mean on a COA?: A result on the powder as supplied, including its water and counter-ion, rather than on the pure substance. As-is copper and peptide content are therefore below the theoretical figures.

Analytical methods

The tests on a batch COA and what each one shows.

HPLC purityWhat does HPLC purity measure?: The main peptide peak's share of the peptide-related signal in reversed-phase HPLC. It does not measure copper, water or acetate.
MS identityWhat does MS identity confirm?: Mass spectrometry confirms that the peptide has the expected mass, i.e. that it is the peptide named. It does not say how much copper is bound.
Bacterial endotoxinWhat is the endotoxin result on a COA?: The amount of bacterial endotoxin measured in the batch, reported on every batch COA of our stocked products.
FillWhat does fill mean on a vial COA?: The measured amount of material per vial compared with the labelled amount.
ICP and AASinductively coupled plasma, atomic absorptionHow is copper content measured?: ICP-OES, ICP-MS and atomic absorption measure total copper as a mass percentage, whatever the copper is bound to. Combined with peptide content they give the Cu²⁺ : peptide ratio.
Lyophilizedfreeze-driedWhat does lyophilized mean?: Freeze-dried: water is removed under vacuum, leaving a dry powder sealed in the vial.

Ordering

The words on a quote and an order: kit, batch, minimum order.

KitWhat is a kit?: Our selling unit: 10 vials of one product and one strength. The minimum order is one kit per product and strength.
Batch and batch COAWhat is a batch COA?: A certificate of analysis issued for one production batch and carrying its batch number. Ours report HPLC purity, MS identity, bacterial endotoxin and fill.
Written quoteWhat does a quote include?: The unit price by the kit, tiered by the number of kits of each product and strength, plus shipping and lead time.

The longer explanations, with sources, are in the guides and notes.

Next step

Tell us the product, strength and number of kits.

Add the destination country and the documents you need. We reply within 24 hours with a written quote: unit price by the kit, shipping and lead time.