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Education Hub

Understand exactly what you’re buying.

Sourcing research peptides should be transparent. This hub explains how to read a Certificate of Analysis, why independent HPLC and mass-spec testing matter, how to vet any supplier, and how lyophilized material is stored — so you can buy with confidence.

See our certificatesHow to vet a supplier
Read a COA

How to read a Certificate of Analysis

A COA is the lab report for your exact batch. Here's a sample, annotated — hover any line to see what it means. Every batch we sell publishes these figures on the Lab Testing page.

Check these 3 things in 30 seconds:
  • 1 Purity is ≥99% by HPLC
  • 2 Identity is confirmed by MS
  • 3 The batch number matches your vial
Independent Lab CERTIFICATE OF ANALYSIS

Identity & Purity Report

1 Batch / Lot number #PP-2407
2 Purity (HPLC) 99.4%
3 Identity (MS) Confirmed
4 Net peptide content ~92%
5 Counter-ion Acetate
6 Water content (KF) < 6%
7
HPLC chromatogram — one sharp peak = high purity
  1. 1
    Batch / Lot number

    A unique code for this exact production run.

    ✓ Good sign: Matches the number printed on your vial.
  2. 2
    Purity (HPLC)

    The percent of target peptide vs impurities, measured by HPLC.

    ✓ Good sign: ≥99% with one dominant peak.
  3. 3
    Identity (MS)

    Mass spectrometry confirms the molecule matches the label.

    ✓ Good sign: Observed mass equals the theoretical mass.
  4. 4
    Net peptide content

    How much of the vial is actual peptide vs salt & water.

    ✓ Good sign: Stated openly, not hidden.
  5. 5
    Counter-ion

    Peptides ship as a salt; acetate is usually preferred to TFA.

    ✓ Good sign: Acetate, and clearly disclosed.
  6. 6
    Water content (KF)

    Residual moisture in the freeze-dried powder, by Karl Fischer.

    ✓ Good sign: Low and reported.
  7. 7
    HPLC chromatogram

    The purity trace itself — one tall, sharp peak means high purity.

    ✓ Good sign: Single sharp peak, few shoulders.
Independent testing

Why third-party HPLC & MS testing matters

There are two separate questions to ask about any vial: is it the right molecule? and how much of it is actually the target rather than impurities? Two techniques answer them.

HPLC → purity

High-Performance Liquid Chromatography separates everything in the vial and measures what fraction is the target peptide. The output is the purity percentage; one tall, sharp peak with little else means few impurities.

MS → identity

Mass spectrometry weighs the molecule. Matching the measured mass to the peptide’s theoretical mass confirms you have the correct sequence — not a mislabeled, truncated or substituted product.

Third-party → credibility

An independent, accredited lab has no incentive to inflate a figure, so its results are verifiable. In-house-only numbers can’t be confirmed. A batch-specific COA from a third party is the credible standard.

Red flags when comparing suppliers: no COA at all · one generic COA reused for every batch · purity quoted with no chromatogram or method · in-house-only testing · identity (MS) never reported.
Purity

What a purity figure really means

Purity is the single most important number on a COA. Here’s how to read the scale when comparing suppliers.

Below 95%

Significant impurities. For a quality research reagent this is a red flag — ask why the figure is low and whether a COA exists at all.

95–98%

Acceptable for some applications, but small impurity fractions can still affect sensitive research.

≥99% — our standard

High-grade material with minimal impurities. This is the threshold every batch we release must meet or exceed.

Buyer’s checklist

How to evaluate a peptide supplier

Use this to vet anyone — including us. A trustworthy research supplier should clear every item on the left and none on the right.

Green flags

  • Batch-specific COAs, published and downloadable
  • Independent, accredited testing lab
  • Both purity (HPLC) and identity (MS) reported
  • Transparent storage, handling and sourcing
  • Clear research-use-only policy
  • Real business identity, contact and support
  • Domestic (Canadian) fulfilment & tracking
  • Secure checkout and a real privacy policy
  • Realistic language — no disease or efficacy claims

⚠ Red flags

  • No COA, or “we can’t share it”
  • The same COA attached to every product
  • In-house-only testing, or no method stated
  • Vague or hidden sourcing
  • Health, medical, “cycle” or dosing advice
  • No research-use policy anywhere
  • Prices that are implausibly low
  • No business name, address or contact
  • Claims to “diagnose, treat or cure” anything
Storage & stability

How lyophilized peptides stay stable

Peptides ship freeze-dried for a reason. Understanding why helps you keep research material in good condition once it arrives.

What lyophilization does

Freeze-drying removes water and locks the peptide into a dry, stable powder. With little moisture present, the chemical reactions that degrade peptides slow dramatically — which is why it’s the standard form for shipping and storage.

Storing the powder

Keep the sealed vial cold, dark and dry, ideally with the included desiccant. Minimise temperature swings, and store colder for longer-term integrity. Always follow any batch-specific note on the COA.

What degrades peptides

Heat, light/UV, moisture, oxidation, microbial contamination and repeated freeze–thaw cycles. Material held in solution is generally less stable than the lyophilized powder, so labs commonly aliquot to avoid repeated thawing.

No reconstitution or dosing guidance. Because products are research-use-only, we describe storage of the supplied material only and do not provide reconstitution recipes, dosing, or administration instructions. For preparing in-vitro stock concentrations, see the molarity reference below.
Glossary

Key terms, in plain English

Peptide
A short chain of amino acids linked by peptide bonds — essentially a small protein fragment.
Lyophilized
Freeze-dried into a stable powder. Peptides are shipped lyophilized to preserve stability during transit and storage.
COA
Certificate of Analysis — the lab document reporting a batch’s purity, identity and other quality parameters.
HPLC
High-Performance Liquid Chromatography, the standard method for quantifying peptide purity.
Mass spectrometry (MS)
An analytical method that confirms a peptide’s identity by measuring its molecular mass.
Molecular weight (MW)
The mass of one mole of the molecule, in g/mol. It is required to convert between mass and molar concentration when preparing in-vitro solutions.
Molarity
The molar concentration of a solution (moles of solute per litre), expressed in M, mM, µM or nM. Common in in-vitro assay work.
Counter-ion
The salt form a peptide is supplied in (commonly acetate or TFA). It contributes to gross weight but is not peptide.
Net peptide content
The true peptide mass in a vial after subtracting counter-ion and residual water.
Reference standard
A well-characterised material used by a lab to calibrate measurements and confirm method accuracy.
ISO-accredited lab
A laboratory independently certified to international quality-management standards, giving its results credibility.
Cold chain
Temperature-controlled handling and shipping used to keep sensitive material stable from warehouse to door.
Desiccant
A drying agent included with lyophilized material to absorb moisture and protect stability.
Freeze–thaw cycle
Each time material is frozen and thawed it can degrade slightly; researchers minimise cycles to preserve integrity.
In-vitro
Latin for “in glass” — experiments performed outside a living organism, e.g. in cell culture or a test tube.
Research use only
Intended exclusively for in-vitro laboratory research by qualified professionals — not for human or veterinary use.
FAQ

Common questions

What is a Certificate of Analysis (COA)?
A COA is a lab-issued document that reports the measured quality of a specific production batch — most importantly its purity (by HPLC) and identity (by mass spectrometry), along with the batch number, appearance and other parameters. A credible COA is tied to the exact batch you receive, not a generic sample.
Why does third-party testing matter more than in-house testing?
An independent, accredited laboratory has no commercial incentive to inflate a result, so its figures are verifiable and credible. In-house-only numbers cannot be independently confirmed. The trustworthy standard is a batch-specific COA from a third-party lab reporting both purity and identity.
What does “≥99% purity” actually mean?
It means HPLC measured at least 99% of the sample to be the target peptide, with under 1% impurities. For it to be meaningful it should be batch-specific and accompanied by the chromatogram and the testing method — not quoted as a generic marketing figure.
How should lyophilized peptides be stored?
Keep the sealed, freeze-dried vial cold, dark and dry, ideally with the included desiccant, and avoid repeated temperature swings. Colder storage preserves integrity for longer. Always follow any batch-specific storage note on the COA. (We do not provide reconstitution or administration guidance, as products are research-use-only.)
How do I evaluate a peptide supplier?
Look for batch-specific published COAs from an independent accredited lab reporting both HPLC purity and MS identity, transparent storage and sourcing, a clear research-use-only policy, real business identity and support, and realistic language with no health, disease or dosing claims. Treat missing COAs, generic “one COA for everything” documents, and medical claims as red flags.
Research use only. Nothing on this page is medical advice or administration guidance, and nothing is intended to diagnose, treat, cure or prevent any condition.

Verify quality, then prepare your work

Read the COA before you buy, and use the in-vitro molarity & dilution reference to plan stock solutions for the bench.

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