Endotoxin and Sterility Testing Documentation for Research Peptides
When a batch record for a research-use-only peptide includes an endotoxin result or a sterility report, those are additional analytical documents that sit alongside the purity and identity results on a Certificate of Analysis (COA). This page explains what those documents typically state, the methods they name, the units and pass/fail format they report in, and how a buyer matches them to a specific lot. It is a documentation and logistics guide for UK research buyers, not a usage guide.
Research use only. Not for human or animal consumption. This page describes what laboratory reports contain and does not describe any use, effect, or outcome of any compound.
What these documents are
Endotoxin and sterility are two separate analytical tests, each producing its own dated report or its own line on a wider COA. They are distinct from the purity (HPLC) and identity (LC-MS) results that confirm what a material is and how much of the sample is the target component, which are covered in hplc purity vs ms identity.
- An endotoxin report states a measured value against a method, expressed in endotoxin units (for example EU/mg or EU/vial), with a pass or fail against a stated specification.
- A sterility report states the method used and a pass or fail outcome for the tested sample, with the incubation or test period named.
Like any analytical document, each is only evidence about a specific batch when it carries a lot number, a method, and a report date.
The methods these reports name
A credible report names its method rather than printing a bare result. For endotoxin, the commonly named analytical method is the LAL (Limulus Amebocyte Lysate) assay, sometimes reported in gel-clot, turbidimetric, or chromatographic formats. The report should state which format was used and the specification the value is checked against.
For sterility, the report names the test procedure followed and the media and incubation period over which the tested sample was observed. Some reports reference a recognised compendial procedure as the analytical standard the method follows.
As with HPLC and LC-MS, the underlying principle is the same: a named method plus a stated specification plus a measured outcome is interpretable; an unattributed badge is not. The same reasoning applied to identity confirmation is set out in lc ms identity confirmation explained.
How results are reported
These tests report differently from a purity percentage:
| Document | Typical method named | Typical reporting format |
|---|---|---|
| Endotoxin | LAL assay (gel-clot / turbidimetric / chromogenic) | Numeric value in EU units, plus pass/fail vs specification |
| Sterility | Named test procedure | Pass/fail outcome for the tested sample, with test period |
A complete endotoxin line states the detected value, the units, the specification limit, and the pass/fail call against that limit, tied to a lot. A sterility line states the method, the test period, and the outcome. A result with no units, no specification, and no method named cannot be read, the same way a bare "identity confirmed" cannot, as discussed in what is a coa peptide.
Matching the report to the vial
An endotoxin or sterility report is only evidence about the vial in front of you if it is tied to that exact lot. The logistics checks are the same as for any batch document:
- Lot-to-label match. The lot or batch number on the report must equal the batch printed on the vial label. A report for another lot describes another vial. The distinction between these identifiers is covered in lot number vs batch number.
- A queryable batch library. A buyer should be able to look up a lot and retrieve the documents held against it, rather than being sent a single cropped image. Why an image alone is insufficient is explained in coa screenshot not verification.
- Report date present. Each document should carry a date so it can be tied to the specific batch run.
- Independent versus supplier-issued. Where a report is produced by a named independent laboratory, it is a separately sourced figure rather than a self-reported one; the distinction is set out in third party peptide testing labs.
How Index records these documents
Where an endotoxin or sterility report is held for a lot, Index files it as a separate named document on the batch record, with its method, its reported value or outcome, and its report date. The lot number on each document is matched to the vial label before dispatch, and any batch with missing or unmatched documentation stays in manual review rather than being listed. The full pre-listing process is described in verify peptide supplier uk.
Research use only. Not for human or animal consumption.
FAQ
What does an endotoxin report for a research peptide state?
It states a measured value against a named method, typically the LAL (Limulus Amebocyte Lysate) assay, expressed in endotoxin units such as EU/mg or EU/vial, together with a specification limit and a pass or fail call against that limit. To be interpretable it should also carry the lot or batch number and a report date. Research use only. Not for human or animal consumption.
What method is named on endotoxin reports?
The commonly named analytical method is the LAL (Limulus Amebocyte Lysate) assay, which may be reported in gel-clot, turbidimetric, or chromogenic formats. A credible report states which format was used and the specification the result is checked against, rather than printing a bare number with no method.
How is a sterility report different from a purity result?
They are separate measurements. A purity result, usually from HPLC, reports how much of the sample is the target component as a percentage. A sterility report names a test procedure and states a pass or fail outcome for the tested sample over a stated test period. A complete batch record can hold both as separate named documents, each tied to its method.
Are endotoxin and sterility reports the same as a COA?
They are additional documents that can sit alongside a Certificate of Analysis rather than replacing it. A COA typically reports purity and identity; endotoxin and sterility are separate analytical reports. Each is only evidence about a specific batch when it carries a lot number, a named method, and a report date that can be matched to the vial label.
How do I check an endotoxin or sterility report belongs to my vial?
Match the lot or batch number on the report to the batch printed on the vial label, confirm the document carries a report date, and look it up in a queryable batch library rather than relying on a single cropped image. A report for a different lot describes a different vial. See the lot-to-label matching steps under verify peptide supplier UK.
Research use only. Not for human or animal consumption.