Home / Methodology
Last reviewed: May 15, 2026 · Reviewed by Dr. Tshering Pedon
Most product pages tell a buyer what a peptide is supposed to be. Far fewer tell the buyer how the company that made it actually goes about making it, what gets tested at the end, and what the buyer can confirm on their own. This page does the second thing.
The framework
Question 1
What's actually in the vial?
Question 2
How does it arrive intact?
Question 3
What can the buyer verify without taking Koi's word for any of it?
The rest of this page works through those three questions in order, with enough chemistry to be honest and enough structure to be useful.
Koi Peptides Canada is a research-use supplier. The materials described here are intended for in vitro laboratory research and are not authorized for human or veterinary use. The methodology supports that use case. It is not GMP-grade, and Koi does not represent it as such.
Question 1
Short answer
The short answer is a lyophilized peptide of a specific sequence, purified to research-grade specification, with the counter-ion form, residual moisture, and impurity profile documented per batch on the Certificate of Analysis. The longer answer is the chemistry and analytical work that produces that result.
Research peptides are assembled one amino acid at a time on a solid support, using a method called solid-phase peptide synthesis. The technique was developed by Bruce Merrifield, who received the 1984 Nobel Prize in Chemistry for it (Journal of the American Chemical Society, 1963). It remains the industry standard for peptides up to roughly 50 residues, which covers the entire Koi catalogue and most research peptides on the global market.
A few practical things follow from how SPPS works. The peptide grows from its C-terminal end, with each new residue protected at the side chain and at the amino terminus to prevent it from coupling with itself or with the wrong site on the growing chain. The protections are removed at controlled steps. Couplings are driven by activating reagents (commonly HATU, HBTU, or DIC with Oxyma) that turn each new amino acid into a form that reacts cleanly with the chain. Between every coupling and deprotection, the resin is washed to clear excess reagents.
The work is done on automated synthesizers under written standard operating procedures. Every run produces a synthesis batch record that captures the resin used, the amino acid lots, the coupling reagents, the operator, the date, and any deviations. This is the document that lets Koi trace a finished vial back to its starting materials months or years after release.
For sequences that resist standard chemistry (long peptides, those prone to aggregation, those with difficult residues), the lab applies additional measures: double couplings, pseudoproline dipeptides to break up problematic secondary structure, or microwave-assisted coupling. The synthesis route chosen for each compound is reproducible across batches by design.
Once the full sequence is assembled, the peptide is cleaved from the resin in a single chemical step using a trifluoroacetic acid (TFA) based cocktail. The cocktail simultaneously cuts the peptide from the solid support and removes the side-chain protecting groups. Scavengers like triisopropylsilane and 1,2-ethanedithiol are added when oxidation-sensitive residues (cysteine, methionine) are in the sequence.
The crude peptide at this point is between 60 and 85 percent pure by HPLC. The remaining 15 to 40 percent is a mix of truncated sequences (where one amino acid failed to couple), deletion sequences (where one was skipped), oxidation products, and small byproducts from the cleavage step itself.
Preparative reversed-phase HPLC separates the target peptide from this background. The standard setup uses a C18 column, a water/acetonitrile gradient with 0.1% TFA, and UV detection at 214 nm. Fractions are collected at a purity threshold, each one re-analyzed by analytical HPLC and mass spectrometry, and only the fractions that meet the spec are pooled. Fractions that fall short are either repurified or discarded.
What comes out of this stage is purified peptide in solution, as a TFA salt, at the catalogue specification of ≥99 percent by HPLC. The TFA counter-ion can account for 10 to 25 percent of the dry mass at this point, depending on how many basic residues the peptide carries (Roux et al., Journal of Peptide Science, 2008). For applications where TFA could interfere (some cell culture work, dose calculations that need to be exact), Koi performs salt exchange to acetate or chloride. The counter-ion form on every batch is documented on the COA.
The purified peptide solution is frozen and dried under reduced pressure. Lyophilization removes water without exposing the peptide to heat or chemical stress, which is why it's the standard preservation method for synthetic peptides. The dry powder that comes out the other side is stable at ambient temperature for the duration of standard shipping, and stable at -20°C for the long-term storage window documented on the product label.
Vials are filled to specified mass, sealed, crimped, and labelled with product name, sequence, lot number, fill weight, storage instruction, and the research-use statement. The fill weight is gross mass. The net peptide content (the actual amount of target peptide after accounting for counter-ion, water, and any residual impurities) is reported separately on the COA, because it's the figure that matters for any quantitative work.
Every batch goes to an independent third-party analytical laboratory before it leaves Koi. The lab runs the analytical panel and issues the Certificate of Analysis under its own letterhead, with a unique verification ID per submission. The panel covers:
The analytical panel covers
Identity by electrospray ionization mass spectrometry, with observed mass compared against theoretical monoisotopic mass within ±1 Da on a quadrupole instrument
Purity by analytical HPLC, area percent under specified method conditions, with the chromatogram included on the COA
Net peptide content by UV detection at 205 or 280 nm against calibrated standards (Anthis & Clore, Protein Science, 2013)
Bacterial endotoxin by USP <85> / Ph. Eur. 2.6.14, numerical result in EU/mg with method specified (mAbs 2025)
Residual solvents by gas chromatography against ICH Q3C limits
Heavy metals by ICP-MS where the synthesis route used catalysts
Why independence matters
The independence of the testing lab is the part that turns the COA from a vendor claim into a verifiable record. A failing result from an in-house QC operation can be quietly discarded. A failing result from an independent lab generates a record at the lab that exists outside Koi's control. This is the structural difference, not just the wording.
Question 2
Lyophilized peptides are remarkably stable in transit. With water removed, the chemistry and microbiology that drive degradation are essentially shut down, and the dry cake holds its analytical profile across normal shipping timeframes. This is the property that lets Koi ship at ambient temperature for most Canadian routes without compromising the material.
For domestic Canadian orders moving through standard transit windows, vials ship in protective packaging without an active cold chain. The buyer's responsibility for cold storage begins on arrival at the receiving end. For long-distance routes, summer heat windows, or any shipment where peak transit temperatures could exceed comfortable ambient, Koi adds thermal packaging at no charge. The decision is made by the shipping team per order based on the route and the season, not as an upcharge.
A typical Koi shipment contains the vials, sealed and labelled, and a storage and handling reference card. The carrier and tracking information arrive by email separately. Customs and research-use declarations are included on the few international orders that ship from the Canadian operation.
What the buyer does on arrival matters as much as what Koi does before shipment. Lyophilized vials should go directly into -20°C storage on arrival for the longest documented stability. Once reconstituted in bacteriostatic water or buffer, the peptide is stable for a shorter window (typically a few weeks at 2 to 8°C, depending on the compound and the buffer chosen). The COA and the storage card both document the specific stability windows for the product received.
Question 3
This is the question that separates a vendor with documentation from a vendor with marketing copy.
For any lot Koi has shipped, the buyer can pull and verify the following without going through Koi:
The batch-specific COA for the exact lot number printed on the vial was retrieved through the COA Library
The HPLC chromatogram with method conditions, retention time, integration, and area percent visible on the document
The mass spectrum with observed mass against theoretical mass for the sequence
The endotoxin results in EU/mg with the test method specified
The third-party verification ID can be checked directly against the testing lab's own records
The net peptide content is reported separately from purity, with the method noted
The counter-ion form and any residual solvent or heavy metals data, where the synthesis route required them
The COA Library keeps historical records accessible. If a researcher needs to confirm what was used in an experiment six months or two years after the order, the same document they pulled at order time can be pulled again. This is the operational record that supports reproducibility on the buyer's side.
Honesty about scope is the other side of the documentation story. Koi Peptides Canada is a research-use supplier operating in a specific tier of the market. The boundaries are these:
Koi does not hold a Drug Establishment Licence from Health Canada under Division 1A of the Food and Drug Regulations. Koi does not manufacture, package, label, distribute, import, or wholesale drugs for human use.
Koi's facility is not registered as a drug manufacturer, and Koi's analytical program is not validated to the standard required for human therapeutic use under Division 2 of the Food and Drug Regulations. Pharmaceutical-grade peptides carry chain-of-custody documentation, sterile manufacturing, validated methods filed with regulators, and ICH stability data that Koi does not provide.
Koi is not a compounding pharmacy. Compounding for human use in Canada is regulated by provincial pharmacy regulatory authorities. Koi does not prepare patient-specific formulations and does not dispense without prescriptions.
Koi does not certify sterility under USP <71> or Ph. Eur. 2.6.1. The lyophilized synthesis process is low-bioburden by design, but the material is not represented as sterile.
Koi does not test for viral clearance, mycoplasma, or other contaminants relevant to clinical biologics. These tests apply to materials derived from biological sources, not to chemically synthesized peptides.
Koi materials are not for human or veterinary use. Every product page and every COA carries the research-use statement. Health Canada's April 9, 2026, advisory was explicit that "research use only" labelling does not exempt a product from regulatory requirements when the actual intended use is human consumption. Koi sells into the research-use framework as the framework is designed: laboratory work, in vitro studies, and analytical chemistry. Anything outside that scope sits outside what Koi supplies.
In summary
A vial of Koi peptide is a piece of analytical chemistry with a documentation trail behind it. The synthesis is run under written procedures with batch records. The purification meets a published specification. The analytical work is done by an independent lab whose results the buyer can verify directly. The packaging keeps the material within specification through standard transit. The storage and handling instructions are honest about the limits.
A Canadian researcher buying from Koi gets material that supports reproducible research because every step in the chain is documented and every claim is verifiable. That's the standard the methodology was built for.
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