Buyer guidance
CAS Numbers, Batch IDs, and HPLC Purity: Verifying a Research Peptide's Identity
What CAS numbers, batch identifiers, and HPLC purity data actually tell you about a research peptide — and how to verify identity before you rely on a result.
In peptide research, a result is only as trustworthy as the material behind it. Three pieces of information do most of the work in establishing what a vial contains: the CAS number, the batch identifier, and the analytical purity on the Certificate of Analysis. Everything supplied is for laboratory research use only and is not for human or veterinary use.
The three identifiers
| Identifier | What it tells you |
|---|---|
| CAS number | A unique registry number for the chemical substance itself, fixing identity independent of any brand or product name. |
| Batch / lot ID | Identifies the specific production run, tying your material to the exact analytical testing performed on that run. |
| HPLC purity | A percentage from HPLC (a liquid-chromatography separation method) indicating how much of the sample is the target peptide versus related impurities. |
Why CAS and batch belong together
A CAS number establishes what the compound is; a batch ID establishes which specific preparation you received. Together they make a result reproducible.
Reading purity honestly
Purity figures mean most when they come with the method behind them. A Certificate of Analysis should show the analytical technique used (commonly HPLC, often alongside mass spectrometry for identity confirmation) rather than a bare percentage.
Checking identity on this site
Compound records carry their CAS number and batch identity; for example, the Semax (10mg) record lists both. See analytical testing, certificates of analysis, and the glossary.
Research use
This guidance is for laboratory research contexts only. It is not medical advice, and the compounds referenced are not for human or veterinary use. If a document you need isn't visible, use the contact form.
Keep moving
Use Guides for the broader documentation model, Research Notes for catalog-adjacent commentary, and the catalog when you need the live product record or current ordering status.
Related reading
Published East Coast Labs notes stay connected to the storefront.
These notes stay reachable from Guides and Research Notes so updates, support pages, and catalog interpretation remain part of one public reading layer.
Research notes
Endogenous Peptides and Their Synthetic Analogs in Research
How many research peptides derive from naturally occurring molecules — mapping synthetic analogs and fragments like Semax, Selank, TB-500, and CJC-1295 to their parents.
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Growth-Hormone-Axis Research Peptides: GHRH Analogs and Secretagogues
An overview of research peptides studied on the growth-hormone/somatotropic axis — GHRH analogs, ghrelin-receptor secretagogues, and recombinant HGH as a reference protein.