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Home / Quality Standards
Last reviewed: May 14, 2026 · Reviewed by Dr. Tshering Pedon
Koi Peptides' quality standards are built on a single principle: every batch must produce a Certificate of Analysis that holds up to independent verification. That means written specifications with numerical acceptance criteria, analytical methods drawn from established compendia, an independent third-party laboratory issuing the results, retained samples that allow re-testing months or years after release, and a documented protocol for what happens when a batch falls outside specification.
This page sets out the standards Koi applies, the specifications each compound is held to, the verification model behind every COA, and the operational practices that support reproducibility on the buyer's end. The objective is to give researchers a complete picture of how quality is defined, tested, and recorded at Koi, so the analytical record they receive carries the governance behind it as well as the numbers.
Three principles run through every decision in Koi's quality Standards.
Every Koi catalog peptide has a written specification that defines the acceptance criteria for identity, purity, content, and contamination before a batch enters analytical testing. The specification is not adjusted to match the result. A batch either meets the published spec or it does not, and that determination is recorded.
Every analytical method that appears on a Koi COA is run at FreedomDiagnostics, an independent third-party analytical laboratory. The financial relationship is documented and disclosed: Koi pays FreedomDiagnostics for the testing, and FreedomDiagnostics issues the results under its own letterhead. The independence is structural, not just stated.
The HPLC chromatogram on a Koi COA is not a generic graphic. It is the actual chromatographic trace generated by FreedomDiagnostics's instrument on the sample submitted from a specific Koi synthesis lot, with method conditions printed on the trace and the lot number indexed in Koi's COA Library. Any of that record can be re-pulled and verified against FreedomDiagnostics's own files.
These principles separate verifiable quality from claimable quality. Most of the patterns documented across the U.S. research peptide market between 2024 and 2026 (round-numbered purity claims, identical chromatograms across different products, "Endotoxin: Pass" with no numerical result) describe what happens when these three principles are not applied. Koi's Standards is designed around enforcing them.
Every catalog peptide at Koi has a written product specification that defines what an in-spec batch looks like. The specification is the contract between the lab and the buyer. Every result on a COA is compared against the specification, and the comparison is recorded in the batch release record.
The standard Koi specification covers six parameters with the following acceptance criteria:
| Parameter | Method | Acceptance criterion |
|---|---|---|
| Identity (mass) | ESI-MS | Observed mass within ±1 Da of theoretical monoisotopic mass on a quadrupole; within a few ppm on high-resolution MS |
| Purity (HPLC) | Reversed-phase HPLC, UV at 210 or 214 nm | ≥98.0% area percent under specified gradient conditions |
| Net peptide content | UV detection at 205 or 280 nm | Reported numerically per batch, traceable to the calibration standard used |
| Bacterial endotoxin | USP <85> Bacterial Endotoxins Test | Numerical result in EU/mg reported, with the testing method specified |
| Residual solvents | Gas chromatography per ICH Q3C | Within ICH Q3C class 2 and class 3 limits where solvents are used in synthesis |
| Heavy metals | ICP-MS | Reported in parts-per-billion where palladium or other catalysts are used in the synthesis route |
For compounds where additional analytical work is required (post-translational modifications, complex secondary structure, biological activity assays where customer applications demand it), the specification is extended to cover those parameters. Any specification extension is recorded in the product master and applied consistently across batches of that compound.
The two figures buyers should pay attention to on every COA are the area-percent purity and the EU/mg endotoxin number. The first defines what fraction of the material is the target peptide. The second defines how clean it is for downstream cell or tissue work. Both are reported numerically, with method conditions, and both are checked against the published spec on every release.
A Certificate of Analysis is only as credible as the methods that produced the numbers on it. Two questions sit underneath every analytical result: was the method validated for the application, and was it verified to perform in the lab that ran it?
The methods Koi specifies for FreedomDiagnostics to apply are compendial, meaning they are published in established pharmacopeias as validated procedures. The HPLC method for peptide purity, the LAL test for bacterial endotoxin, and the ICP-MS method for heavy metals are all drawn from procedures recognized in the U.S. Pharmacopeia and the International Council for Harmonization guidelines. The validation work for these methods has been completed by the pharmacopeial bodies and published. The relevant USP framework for that validation work is set out in USP General Chapter <1225>, "Validation of Compendial Procedures."
When a validated compendial method is applied in a specific laboratory, the lab is required to verify that the method performs adequately on its instruments, with its reagents, and with the type of sample being tested. The framework for this verification work is USP General Chapter <1226>, "Verification of Compendial Procedures." Verification is not full re-validation; it is targeted demonstration that the method works as intended in the specific conditions of use. FreedomDiagnostics maintains verification records for each compendial method it applies to Koi samples, and those records are part of the analytical chain of custody behind every Koi COA.
Two practical consequences follow from this framework. First, when a chromatogram on a Koi COA shows a target peak at a specific retention time, that retention time can be expected to be reproducible across batches because the method is verified and the system suitability checks are documented. Second, when an endotoxin result on a Koi COA reports a number in EU/mg, that number is traceable to a USP-recognized procedure with documented performance characteristics, not a proprietary in-house variant. The numbers carry the weight of the methods behind them.
Koi's relationship with FreedomDiagnostics is structured as an independent third-party analytical contract. Samples are sent from Koi's synthesis facility to FreedomDiagnostics. Analytical work is performed by FreedomDiagnostics personnel on FreedomDiagnostics's instruments. Results are issued under FreedomDiagnostics's letterhead with a unique verification ID per submission.
The verification ID is the key element. Every Koi COA carries the FreedomDiagnostics ID for the analytical work that supports it. Any buyer who wants to confirm that the COA is authentic can take the verification ID and check it directly against FreedomDiagnostics's own records. This is the same workflow any QC lab in a regulated industry uses to authenticate a third-party result, and it is the verification mechanic that separates a result issued by an independent lab from a result published by the manufacturer on its own.
Independence matters because conflict of interest is the single largest variable in COA reliability across the industry. A failing result from an in-house lab can be re-run, re-integrated, or quietly discarded; there is no external party with a stake in catching the discrepancy. A failing result from an independent lab generates a record at the third-party lab that exists outside the manufacturer's control. The Koi-FreedomDiagnostics relationship is designed so that this record exists for every batch, not selectively.
Independent analytical labs operating in this space typically work under ISO/IEC 17025:2017, "General requirements for the competence of testing and calibration laboratories," which is the international standard governing competence for testing labs. The standard covers personnel qualification, equipment calibration, method validation records, sample handling, reporting, and the management system that supports all of it. Asking a third-party lab about its 17025 status is the standard due-diligence question for anyone evaluating analytical credibility, and the answer should be a documented one.
Not every synthesis run produces material that meets specification. Solid-phase peptide synthesis at scale produces variation. A batch that passes the specification is released for sale. A batch that does not is handled through a documented non-conformance protocol.
The protocol has three stages.
First, investigation. When a result falls outside the specification, the testing is reviewed with FreedomDiagnostics to confirm the result is real and not the consequence of a method anomaly. The original analytical record is reviewed. Where appropriate, the sample is retested. If the re-test confirms the original out-of-spec result, the batch enters the next stage.
Second, root cause review. The synthesis batch record is reviewed against the analytical result. A purity result below specification typically traces to a coupling failure, an incomplete cleavage, or a purification yield that did not adequately separate a closely-related impurity. An endotoxin result above specification typically traces to a water source, a vessel contamination, or a handling step. The root cause review identifies the source so it can be addressed in the next run.
Third, disposition. A batch that fails specification is either reworked (re-purified through a second preparative HPLC pass and re-tested) or rejected. A rejected batch is not released for sale, is removed from the inventory record, and is destroyed under a documented destruction record. The decision between rework and rejection is made on the basis of the failure mode: a purity miss by 1 to 2 percentage points is typically reworkable; a substantial mass-spectrum discrepancy is not.
The output of this protocol is documented and retained. The investigation, root cause, disposition, and destruction records are linked to the batch record and the COA file for the synthesis lot. If a buyer later asks why a particular catalog SKU was unavailable in a particular month, the answer can be traced back to the specific batch failure and the action taken.
This is the part of a quality standard that does the most operational work and gets the least public attention. The willingness to reject a batch is the practical test of whether a specification is written before the test or after it.
Every Koi synthesis lot generates a documentation chain that supports analytical traceability for the operational life of the material. The chain has four components.
Generated at the time of synthesis. Captures the date, the operator, the resin lot, the amino acid lots, the coupling reagent lots, the in-process observations, and any deviations from the standard procedure. Retained against the lot number.
Generated by FreedomDiagnostics. Includes the chromatographic trace, the mass spectrum, the endotoxin measurement, and any residual solvent or heavy metals data. Issued under the FreedomDiagnostics verification ID. Retained against the lot number both at FreedomDiagnostics and at Koi.
Generated when the batch is released for sale. Captures the comparison of the analytical result against the written specification and the approval signature. Retained against the lot number.
A small portion of the lot is set aside and stored under documented conditions for the operational life of the product. If a quality question arises about the lot after release, the retention sample is available for re-testing against the original record. Retention sample storage conditions are documented, and the chain of custody from synthesis through storage is maintained.
Together, these four records constitute the full traceability dossier for a Koi synthesis lot. Any buyer with a lot number printed on a vial can pull the COA through Koi's COA Library. Any auditor or regulator with appropriate authority can request the underlying batch record, analytical record, release record, and retention sample.
The functional consequence of this system is reproducibility. If a researcher uses Koi material in an experiment in June 2026 and needs to confirm the analytical profile of that exact material when writing the manuscript in November 2027, the documentation supporting the original COA remains accessible and verifiable.
The research peptide market spans a wide range of quality tiers. Understanding where Koi operates inside that range is part of evaluating whether the standards fit a particular research application.
Tier 1
Manufactured under cGMP per FDA 21 CFR 211, with full chain-of-custody documentation, sterile manufacturing environment, validated analytical methods filed with regulatory agencies, full ICH stability data, and clinical-grade documentation supporting human therapeutic use. This is the tier occupied by companies like Bachem, PolyPeptide, and CordenPharma, supplying API to pharmaceutical sponsors.
Koi does not operate at this tier.
Tier 2
Synthesized under written SOPs, tested against published specifications using compendial methods, with results issued by an independent third-party laboratory and traceable to documented analytical records. Suitable for in vitro and preclinical research applications where verified analytical purity, identity, content, and endotoxin data are required.
This is the tier Koi operates in.
Tier 3
Tested in-house, with results published by the manufacturer on its own letterhead. May be technically accurate; cannot be independently verified at the lot level without sending material back to the manufacturer.
Tier 4
Generic product-level COAs (one document covering an entire SKU regardless of batch), missing chromatograms, missing endotoxin data, or "Pass/Fail" results without numerical values. Functionally, the bottom of the market.
Tier 2 is where serious research-use sourcing should sit. It carries the analytical credibility that supports reproducibility without the pharmaceutical-grade documentation burden that Tier 1 requires for materials that are not destined for human therapeutic use.
The framework Koi operates within is built specifically around Tier 2 requirements: independent verification, compendial methods, written specifications, retained samples, and lot-level traceability.
A quality standard is not a static document. Methods get updated, instruments improve, and the regulatory landscape shifts. Koi tracks four sources of change against the Standards.
When the U.S. Pharmacopeia revises an established chapter, the change flows through to the specifications and methods Koi applies. The shift toward recombinant Factor C methods for endotoxin testing under USP <86> and the broader move toward animal-free analytical methods are examples of this kind of evolution.
FDA enforcement actions, ICH guideline revisions, and state pharmacy board guidance all carry signals for how research peptide quality should be defined. Tracking these developments and updating SOPs in response is part of the operational rhythm.
New analytical techniques, better detection limits, and improvements in instrument sensitivity all create opportunities to strengthen the analytical panel. When a stronger method becomes accessible at FreedomDiagnostics, the specification is updated to reflect it.
When a researcher reports a result that does not match the COA expectation, the report is investigated. Where the investigation surfaces a real gap in the analytical panel or a real ambiguity in the documentation, the standards are updated to address it. This is the slowest feedback loop in the system, and the most important one.
The Koi quality standards will look different in 2027 than they do in 2026, and different again in 2030. The principles will not change: specifications written before the test, results issued by an independent lab, every claim traceable to a record. The methods and the thresholds will get tighter over time.
The publicly verifiable artifacts of the Koi quality Standards are:
The verification step is short. A researcher who wants to confirm a Koi result takes the lot number from the vial, pulls the COA, takes the FreedomDiagnostics ID from the COA, and checks it against FreedomDiagnostics's records. If the ID resolves to a result that matches what is on the COA, the document is authentic. If it does not, Koi wants to know about it immediately.
This is the verification model the rest of the research peptide market needs to move toward, and the model Koi is built around from the ground up.
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• ≥99% purity target • Third-party tested • COA per batch • Fast US shipping