Material that behaves the same way twice.
A reference standard is only useful if the next vial matches the last. A supplier's specification, analysis and documentation are what keep variability inside your experiment instead of inside your inputs.
Defined specification
01.1Sequence, molecular formula, monoisotopic mass, counter-ion, water content and appearance should be fixed before a lot is accepted — not described after the fact.
Independent analysis
01.2Identity and purity should be confirmed by an independent laboratory, with chromatograms and spectra available in full rather than summarised to a single figure.
Documented chain
01.3Synthesis site, fill date, storage condition and shipping temperature should be recorded against the lot number printed on the vial you receive.
When synthesis and fill move between sites, procedures, equipment and analysts move with them. Ask where yours happen — and whether the answer is the same for every lot.
Every lot is measured before it is named.
Retention time, peak area and mass confirmation should exist for every production lot. Ask to see them. A supplier that cannot produce the chromatogram for the lot in your hand is asking you to take purity on faith.
Three questions worth asking
Read the certificate, not the claim
A purity percentage on a product page is marketing. A lot-specific certificate with the chromatogram attached is evidence. Ask which one you are being shown.
Match the lot in your hand
Documentation should carry the same lot number printed on the vial. Paperwork for the product line, or for a lot you did not receive, tells you nothing about your material.
Ask who did the testing
Identity and purity confirmed by an independent laboratory is a different assurance from a supplier's own QC. Both have a place; only one is arm's length.
What a certificate of analysis should tell you.
Four things are worth checking before you accept any lot. None of them require taking a supplier's word for it.
- 01The lot number matches the vial label exactly.
- 02Purity is stated with the method that produced it — RP-HPLC, and at what wavelength.
- 03Identity is confirmed by mass spectrometry, with the observed mass shown.
- 04Water content is quantified, not omitted. Karl Fischer is the usual method.
Ordering happens on the supplier's site.
Genetic Elements does not sell materials. Leave your details and we will take you through to the supplier that fulfils orders — and send you the documentation checklist to hold them to.
Ordering is fulfilled by an independent partner supplier. We may be compensated for orders placed through this link.