Quality control
Each batch is analyzed and released individually. Purity is measured by HPLC and identity is confirmed by LC-MS, with a certificate of analysis (COA) per batch. Material for scientific research only (RUO).
From synthesis to release
- 01 Síntesis — Production of the peptide by solid-phase synthesis (SPPS).
- 02 Recepción — Inspection of the batch and entry into quality control.
- 03 HPLC — Chromatographic purity by peak area (%).
- 04 Masa (LC-MS) — Molecular identity: expected vs. observed mass.
- 05 Liberación — Only conforming batches are labeled and released.
HPLC analysis
High-performance liquid chromatography separates the components of a sample and quantifies each one with sub-percent precision. It is the standard technique for determining the purity of a peptide.
- Retention time (Rt) — Identifica el compuesto frente a un estándar.
- Area under the curve (%) — Quantifies the purity: fraction of the main peak.
- Peak resolution — Separates the peptide from its related impurities.
- Stable baseline — Confirms the precision and validity of the analysis.
Purity interpretation
The area percentage of the main peak defines the batch's purity band.
- ≥ 99 % — Research grade. It is the sector's reference band.
- 95 – 99 % — Standard grade. Quality varies between suppliers.
- < 95 % — Not recommended. Impurities can alter results.
Identity by LC-MS
Purity is not enough: a compound can be pure and still not be the correct one. Mass spectrometry coupled to chromatography (LC-MS) confirms identity by comparing the observed mass with the expected mass of the sequence. A match within the method's tolerance confirms that the batch corresponds to the declared peptide.
What is analyzed in every batch
- Purity by HPLC-UV with detection at 220 nm, the wavelength of the peptide bond.
- Identity by electrospray ionization mass spectrometry (ESI-MS): theoretical mass against observed mass.
- Certificate of analysis (COA) for the specific batch, not for a representative batch.
- Analysis at an independent third-party laboratory, not in-house.
- Laboratory with ISO/IEC 17025 certification.
Un COA leído entero, no un adjetivo. Batch PMX-BPC-2026-041 of BPC-157: purity 99.4% by HPLC-UV at 220 nm, measured as the main peak area over the total area. Identity confirmed by ESI-MS against the theoretical mass of the sequence GEPPPGKPADDAGLV (C62H98N16O22, 1418.70 Da monoisotopic), within the method's tolerance (±1 Da / ±50 ppm). The complete batch chromatogram also shows the integration of the impurities monitored in this peptide: des-Gly1, des-Val15 and the aspartimide/iso-Asp variants at Asp10/Asp11. That certificate can be consulted by batch number at exomapeptides.mx/certificados-analisis, without an account and before purchasing.
Per-batch documentation: what you can demand
A percentage on a product page is not documentation. This is what a research-reagent supplier should be able to hand you, and what you can ask us for in writing before buying.
- COA for the exact batch number — The certificate must correspond to the batch printed on your vial, not to «a representative batch» nor the same PDF for the entire presentation. If the number does not match, that document does not describe the material you are holding.
- Full HPLC chromatogram — The entire trace —time axis, baseline, impurity peaks and their integration—, not just the summarized percentage. The summary is precisely what hides the information used to judge a batch.
- MS or LC-MS spectrum with theoretical and observed mass — The two figures side by side. Purity measures what fraction of the sample is a single compound; it does not say that compound is the correct one. That is settled by the mass.
- Actual peptide content — By amino acid analysis (AAA) or an equivalent quantitative method, when molar concentration matters. Purity by HPLC area does not on its own indicate how many net milligrams of peptide the vial contains: the rest of the lyophilized mass may be water, salt and counterion.
- Chemical form and counterion — Acetate, TFA, hydrochloride or another. It changes the net mass of the vial, the solubility and, in cell culture, may change the very result of the experiment.
- Water, residual solvents and net quantity — When the experiment is quantitative. Without these values, the concentration you calculate from the vial's nominal weight is an estimate, not a fact.
- Endotoxins, bioburden or sterility — Assays contracted specifically when they are relevant —work with cell culture or in vivo models—. Neither HPLC nor mass spectrometry demonstrates sterility: they are purity and identity techniques, not microbial load techniques.
- SDS, institutional invoice and shipping conditions — Safety data sheet, invoice in your institution's name, the conditions in which the material traveled and the written policy for an out-of-specification batch.
The batch COA covers the first three points and, when the laboratory reports it, the chemical form and counterion as well. The assays that are not routine — amino acid analysis, water and residual solvents, endotoxins, bioburden, sterility — are quoted and contracted to the laboratory before the material is released. Support handles the SDS and the invoice in your institution's name. Write to us with the compound, the batch number and what you need to demonstrate, and we will tell you what can be documented and how long it takes.
Our standard
- HPLC — Analysis per batch.
- LC-MS — Identity confirmation.
- % per batch — The measured purity is reported in the COA.
- 1 batch = 1 COA — Trazabilidad.
FAQ
What purity do EXOMA peptides have?
The COA of each batch reports its HPLC-measured purity: the percentage of that specific batch, not a catalog figure. Most of the catalog sits above 99%, and when a batch falls below, the measured value is published as is in its certificate rather than being rounded.
How often are the products analyzed?
Each batch is analyzed before being released; analyses from previous batches are not reused. Each vial comes from a batch with its own analytical characterization.
What is the difference between HPLC and mass spectrometry?
HPLC measures purity (what fraction of the sample is the desired peptide versus impurities). Mass spectrometry (LC-MS) confirms molecular identity by verifying that the observed mass matches the expected mass. They are complementary.
Can the batch be checked before buying?
Yes. The certificates are public at exomapeptides.mx/certificados-analisis: search by product or batch number, open the COA and read the measured percentage — no account, no email, before paying. Example: batch PMX-BPC-2026-041 of BPC-157 reports 99.4 % purity by HPLC-UV at 220 nm, with identity confirmed by ESI-MS against the theoretical mass of the sequence GEPPPGKPADDAGLV (C62H98N16O22, 1418.70 Da monoisotopic). The batch's full chromatogram and mass report are downloadable there.
What documentation can I demand with my batch?
The COA matching the batch number printed on your vial (not a representative batch), the full HPLC chromatogram and not just the summarized percentage, the MS or LC-MS spectrum with theoretical and observed mass, the chemical form and counterion (acetate, TFA, hydrochloride or other), and the safety data sheet (SDS) with an invoice in your institution's name. When the experiment requires it, actual peptide content by amino acid analysis, water and residual solvents, and endotoxin, bioburden or sterility assays are contracted as well. Ask for it in writing before buying.
Does HPLC purity tell you how many milligrams of peptide are in the vial?
No. HPLC area purity indicates what fraction of what was injected into the column corresponds to the peptide rather than its impurities, not how much net peptide mass the vial holds. The rest of the lyophilized powder can be water, salt and counterion, and that fraction is not negligible. If your experiment depends on molar concentration, you need amino acid analysis (AAA) or an equivalent quantitative method, contracted separately.
Who performs the analyses?
The analyses are performed in a laboratory with calibrated equipment. The results are verifiable and reproducible under the analytical conditions reported in the batch's COA.