Glossary

Research peptide

A short chain of amino acids produced synthetically and supplied to laboratories for in-vitro and scientific research. Research peptides are not medicines, are not approved for human or veterinary use and are sold only for research.

Research use only (RUO)

A label that limits a product to laboratory research. An RUO product is not intended for diagnosis, treatment, human consumption or veterinary use. Every product in the SPEPS Group catalogue carries this restriction. Read the disclaimer.

Amino acid sequence

The order of amino acids in a peptide chain, written from one end of the chain to the other. The sequence defines which compound a peptide is. Where it is relevant, the catalogue lists it with the molecular data.

CAS number

A unique identifier assigned to a chemical substance by the Chemical Abstracts Service. It lets a researcher match a product to the literature without relying on trade names. Not every peptide has a CAS number; the catalogue shows it where one is assigned. Browse the catalogue.

Molecular formula

The number of atoms of each element in one molecule of the compound, for example carbon (C), hydrogen (H), nitrogen (N) and oxygen (O). Together with the molecular weight it describes the compound in the vial.

Molecular weight

The mass of one molecule of the compound, given in grams per mole (g/mol). Laboratories use it, together with the measured mass from mass spectrometry, to confirm the identity of a peptide.

Lyophilised (freeze-dried)

A peptide from which the water has been removed by freezing and drying under vacuum. The result is a dry powder or cake in the vial, which is more stable in storage and transport than a solution. Peptides in the SPEPS Group catalogue are supplied lyophilised.

Vial

The small sealed glass container in which a peptide is supplied. The vial size in the catalogue (for example 10 mg) is the amount of compound in one vial. The lot number on the vial label links it to its certificate.

Peptide blend

A vial that contains more than one compound, such as GLOW 70 or KLOW 80mg. The catalogue lists the compounds in each blend in the product name.

Lot number (batch number)

The code that identifies one production batch. It is printed on the vial label and on the Certificate of Analysis, so a researcher can match the vial on the bench to the analysis of that exact batch.

Certificate of Analysis (CoA)

A document issued by a laboratory that reports the results of analysing one batch: the compound, the lot number, the date, the methods used and the measured results. SPEPS Group publishes the certificates it holds in one library shared by all five shops. Open the certificate library.

HPLC (high-performance liquid chromatography)

A laboratory method that separates the components of a sample as it passes through a column under pressure. The result is a chromatogram, in which the share of the main peak is reported as the purity of the sample.

Mass spectrometry (MS)

A laboratory method that measures the mass of molecules. Comparing the measured mass with the expected molecular weight confirms that the vial contains the stated compound. It answers a different question from HPLC: identity rather than purity.

Purity

The share of the intended compound in a sample, as measured by the laboratory, usually by HPLC. Purity is a result of one batch, so we state it on the Certificate of Analysis of that batch and not as a general figure on the website.

Peptide content

The share of the total weight in the vial that is the peptide itself, as opposed to water, counter-ions and other residues that are normally present in a lyophilised powder. It is measured separately from purity, for example by HPLC with a CLND or CAD detector.

Endotoxin and bioburden

Endotoxin testing looks for bacterial cell-wall fragments; bioburden testing counts living microorganisms. Some certificates in the SPEPS Group library report these screenings in addition to purity and identity.

Bacteriostatic water

Sterile water containing a small amount of benzyl alcohol, which inhibits bacterial growth. Laboratories use it as a solvent. It is listed in the catalogue as a laboratory supply.

Acetic acid 0.6%

A dilute acetic acid solution used in laboratories as a solvent for compounds that do not dissolve well in water. It is listed in the catalogue as a laboratory supply.

Storage at −20 °C

The usual storage condition for lyophilised peptide vials: frozen, dry and away from light. Cold storage slows the chemical changes that can affect a compound over time.

Missing a term? Ask us at speps.group@protonmail.com. See also the frequently asked questions.