Compliance Disclaimer: Ascenyx Bio LLC sells compounds labeled “For Research Use Only” (RUO). These products are not drugs, supplements, or consumer goods, are not approved by the FDA for any human or animal use, and are not intended for human consumption. All quality, testing, and purity information on this page is provided for the benefit of qualified researchers and laboratories evaluating material for legitimate scientific research. Nothing on this page should be interpreted as a recommendation, endorsement, or instruction for human use of any product sold on ascenyxbio.com.
Our Commitment to Verified Quality
Ascenyx Bio was built on a simple principle: researchers should never have to guess what’s actually in the vial. Every research compound we publish is backed by a lot-specific Certificate of Analysis (COA), generated from third-party laboratory testing using HPLC (High-Performance Liquid Chromatography) and LC-MS (Liquid Chromatography–Mass Spectrometry) — the two analytical methods most widely used across the research peptide industry to establish purity and molecular identity. Purity varies by product and is confirmed lot-by-lot — the exact purity percentage for each unit is documented in its lot-specific COA, available for download on the corresponding product page.
This page explains what that testing actually measures, what a COA contains, and how to verify the documentation for your specific order.
Why Third-Party, Batch-Specific Testing Matters
Peptide synthesis is a precise but variable chemical manufacturing process. Even under tightly controlled conditions, purity, residual solvent content, and trace impurity profiles can differ slightly from one production lot to the next. A testing result from a previous batch — or a generic purity claim not tied to a specific lot — tells a researcher very little about the material actually in their possession.
That is why every product on ascenyxbio.com includes a downloadable, lot-specific COA, linked directly on the product page. Matching the lot number on your product label to the lot number on the COA is the only reliable way to confirm you have the correct documentation for your unit. This is also foundational to research reproducibility: published and internal research protocols depend on knowing precisely what material — and what purity/identity profile — was used in an experiment, so that results can be validated or repeated (Creative Proteomics guide on peptide purity analysis).
What’s Inside a Certificate of Analysis (COA)
A properly documented COA should give a researcher enough information to independently evaluate the material’s quality. At minimum, a rigorous COA includes:
| COA Element | What It Tells the Researcher |
|---|---|
| Batch/Lot Number | Uniquely identifies the specific production run the material came from — critical for matching documentation to the physical product received. |
| Purity Percentage | The measured chromatographic purity of the compound, typically determined by HPLC peak-area analysis. |
| Test Date | When the analytical testing was conducted, allowing researchers to assess documentation currency. |
| Testing Laboratory / Method | Identifies the analytical method(s) used (HPLC, LC-MS, or both) and, where available, the testing facility. |
| Molecular Weight / Identity Confirmation | Where LC-MS is used, confirms the compound’s molecular mass matches its expected identity. |
How HPLC Testing Works
High-Performance Liquid Chromatography (HPLC) is an analytical technique that separates the components of a sample as it flows through a column packed with a solid material (commonly a C18 reversed-phase column), typically using a water–acetonitrile solvent gradient. As different components of the sample travel through the column at different rates, a detector — usually a UV detector set around 214 nm, a wavelength at which peptide bonds absorb strongly — records each component as it elutes, producing a chromatogram of distinct peaks.
Purity by HPLC is generally calculated as the area of the main compound peak divided by the total integrated peak area, multiplied by 100.
This method is highly effective at showing how cleanly a compound separates from other UV-absorbing material in the sample, and a single, sharp, symmetrical peak is generally a strong quality indicator. It’s worth noting that HPLC purity reflects the relative proportion of UV-absorbing material in the main peak — it does not, by itself, confirm the molecular identity of that peak or measure moisture, salt, and counterion content that may also be present in a lyophilized sample. This is why HPLC is typically paired with LC-MS for a complete quality picture. (Source: Creative Proteomics)
How LC-MS Testing Works
Liquid Chromatography–Mass Spectrometry (LC-MS) combines the same chromatographic separation used in HPLC with mass spectrometry detection, which measures the molecular weight of each separated component. As the sample elutes from the column, it is ionized (commonly via electrospray ionization) and analyzed by a mass spectrometer, which determines the mass-to-charge ratio of the resulting ions. This data is then used to calculate the compound’s molecular mass and compare it against the theoretical (expected) mass for that compound.
LC-MS provides two things HPLC alone cannot: identity confirmation (verifying the tested material actually matches the expected compound by mass) and the ability to detect certain co-eluting impurities or mass-shifted variants — such as those resulting from oxidation, deamidation, or incomplete synthesis — that may be present even within what appears to be a single HPLC peak. Together, HPLC and LC-MS give researchers both a purity percentage and a confirmed molecular identity.
What “99% Purity” Means
When a COA reports 99% purity, it generally means that HPLC analysis found that 99% of the UV-absorbing material detected in the sample corresponds to the main compound peak, with the remaining 1% attributable to trace synthesis byproducts or related impurities. Combined with LC-MS mass confirmation, a 99% purity result with a matching molecular weight gives researchers strong, verifiable confidence in both the cleanliness and identity of the compound.
Finding Your Product’s COA
Every product listed on ascenyxbio.com includes a COA download link directly on its product page, organized by lot number. To verify your specific unit:
- Locate the lot number printed on your product’s label.
- Visit the corresponding product page on ascenyxbio.com.
- Download the COA matching that lot number.
- Confirm the batch number, purity percentage, and test date align with your physical product.
If you have questions about locating or interpreting a COA for your order, our team is available at support@ascenyxbio.com.
A Note on Regulatory Status
All compounds referenced on this page and throughout ascenyxbio.com are sold strictly as Research Use Only (RUO) materials. They are not approved by the FDA as drugs, biologics, dietary supplements, or medical devices, and are not intended for diagnostic, therapeutic, cosmetic, or any human or animal use. RUO is a recognized regulatory labeling category for materials intended solely for laboratory and analytical research (Source: U.S. FDA guidance). Regulatory scrutiny of RUO-labeled research compounds has increased industry-wide, with enforcement generally focused on marketing claims that suggest a product’s intended use extends beyond legitimate research — including any implied human health, treatment, or performance claims. Ascenyx Bio’s marketing and product content are limited strictly to regulatory, logistical, and scientific/testing information consistent with RUO status, and purchases are restricted to buyers who certify a legitimate research or laboratory use case.