A Kisspeptin-10 certificate of analysis is a test report for one lot. Read it in order. Match the lot number to the vial and check the test date. Then look at mass near 1302.4, the amide check, purity with the chart, related substances, net peptide content, and the lab that issued it.
- Kisspeptin-10 is C63H83N17O14, average mass near 1302.4, PubChem CID 25240297.
- Two asparagine residues means two independent deamidation sites.
- The C-terminal amide gives a third route to the same one-dalton gain.
- A mass shift of one dalton cannot say which of the three occurred.
- All three can hide inside the main peak on a method not developed for them.
- Tryptophan and tyrosine give a real 280 nm signal, and tryptophan is a liability.
What does a Kisspeptin-10 certificate actually certify?
If you hold a receipt from Tuesday's grocery run, it proves nothing about Friday's. A certificate of analysis for one batch works the same way: it tells you what was checked on that batch and when, and it says nothing about any other batch.
It records what a named laboratory measured on a sample drawn from one lot, on one date, by named methods. It is evidence about that sample rather than a warranty about the vial on your bench.
A specification sheet lists limits a product is supposed to meet, carries no lot number and no results, and describes an intention. A certificate carries both because it describes an event.
A page with no lot number on its face is the first kind whatever its heading says. For this peptide the fields worth most attention are the ones covering related substances, for reasons its sequence makes unavoidable.
- Lot number on the report against the lot number on the vial
- Identity: observed mass against an average near 1302.4
- Three separate routes each add one dalton to this molecule
- Deamidation at either asparagine, or loss of the terminal amide
- Related substances, and whether the method could resolve them
- Purity at 214 nm with 280 nm as a second view
- Accession number confirmed at the issuing laboratory
What mass should the identity result show?
Kisspeptin-10 is a decapeptide, molecular formula C63H83N17O14 with an average mass near 1302.4, cataloged as PubChem CID 25240297.
Three features of the sequence shape everything analytically. It ends in an amide rather than a free acid. It contains two asparagine residues. And it carries both a tryptophan and a tyrosine.
Each of those is a liability or an advantage in a specific, checkable way, and together they explain why this compound's related-substance profile is busier than most in the catalog.
Why do two asparagines matter?
Because asparagine is the residue that deamidates, converting its amide side chain into an acid and adding about one dalton. Having two doubles the opportunity.
The reaction is not equally fast at every site. It depends heavily on the residue that follows: a small one leaves the geometry open and speeds the reaction considerably, while a bulky one slows it.
So a single sequence can carry a fast site and a slow one, and the deamidated products are different molecules that happen to share a mass. On this peptide the plural is the point, and it means the related-substance section of a certificate has more to account for than a single-asparagine peptide would.
How does the terminal amide add to that?
It gives a third site that can gain the same one dalton by a different reaction. Kisspeptin-10 terminates in an amide, and hydrolysing that to a free acid adds about one dalton exactly as deamidation does.
So there are three distinct ways for this molecule to end up one dalton heavier, and a mass measurement alone cannot say which of them happened.
That is a genuinely awkward situation and it is worth stating plainly rather than glossing. The mass tells you something changed. Only a separation, or fragmentation data, tells you where.
Can the separation resolve them?
Sometimes, and the answer depends on the method rather than on the compound. Each of the three products differs from the parent by a small change in charge, so retention shifts slightly for each.
Where the gradient and mobile phase have been developed with these species in mind, they appear as resolved small peaks near the main one. Where they have not, they sit inside it.
This is why the certificate's method line matters more here than on a simpler peptide. A purity figure of 98 percent from a method that resolves the deamidated forms means something quite different from the same figure produced by a gradient that never separated them.
There is a practical way to ask about this without needing to read a chromatogram yourself. Ask the supplier whether the purity method was developed against the deamidated forms specifically. A laboratory that did so will say yes and may name the resolution achieved. One that did not will usually say so plainly, which is a fair answer and a different one from a purity figure presented as though it settled the question.
What do the aromatic residues contribute?
A second detection wavelength, and one more degradation route. Tryptophan and tyrosine both absorb at 280 nanometres, so this peptide gives a real signal there as well as at the usual 214.
Running both is informative. A peak present at 214 but absent at 280 has neither aromatic residue, which places it as a fragment rather than a variant of the whole molecule.
Tryptophan is also the residue most readily oxidised and most readily degraded by light, and it produces several products rather than one. So the same residue that gives a useful analytical handle is also a liability, which is a pattern this catalog repeats.
How do you read the certificate field by field?
Lot number first, against the vial. Then dates, where a test date should follow the fill date and a print date carries no analytical meaning.
Then identity by mass, stated as a number. Purity by reversed-phase HPLC with the chromatogram attached, ideally at both wavelengths. Related substances, which here means deamidated and hydrolysed forms. Net peptide content. Counterion. Water. Appearance last.
Each result needs its method beside it. Purity by area percent, by net peptide content and by amino acid analysis are three different numbers for one vial and they do not agree.
What does the purity figure leave out?
Anything the detector did not see and anything the separation did not separate. Reversed-phase purity is an area percentage of detected material.
Peptides are read at 214 nanometres because that responds to the peptide bond, so peptide impurities show well while salts and water are largely invisible. A vial can be 98 percent pure by area and still be substantially counterion and moisture by weight.
For this compound the resolution limit is the sharper one. Three different one-dalton products can all hide inside a main peak on an undeveloped method, and the reported figure will look entirely healthy.
What is net peptide content, and why does it change the price?
A synthetic peptide ships as a salt carrying a counterion from purification, plus water absorbed because lyophilized peptide is hygroscopic.
The consequence is arithmetic. A vial labeled 5 milligrams may hold 5 milligrams of powder of which a real fraction is salt and water. Net peptide content of 80 percent means 4 milligrams of peptide, and two suppliers quoting the same price for the same nominal size are not selling the same amount.
Ask which basis the label uses. The cost per milligram comparison ranks the catalog on one basis so two quotes can be compared honestly.
What does the certificate not cover?
Everything after the sample was drawn. Storage temperature, light, how long the vial has been open and how it has been handled are all outside it.
All three of this peptide's one-dalton routes continue after release, driven by moisture and accelerated by higher pH and temperature. A lot genuinely clean at test can carry a meaningful proportion of altered material months later.
Because each of those changes is a single dalton on a 1,302-dalton molecule, nothing about the powder announces it. Handling belongs with the storage record rather than the test report.
How do you verify the document is genuine?
Confirm the report at the issuing laboratory rather than with the seller. An independent laboratory issues each certificate against an accession number that resolves on its own site. If the number resolves to a different product, a different lot, or nothing, the document does not describe your material.
Certificates with the verification key removed deserve particular suspicion, and this is not hypothetical in this market. A PDF is easy to edit; a third-party lookup is not.
Lot reports for material supplied here resolve through the certificate verification page, and the sizes carried appear on the Kisspeptin-10 product record.
What is the regulatory position?
There is no FDA-approved drug product containing Kisspeptin-10 and no United States pharmacopeial monograph defining what an acceptable batch is. The specification a lot is released against is the supplier's own.
For a peptide with three separate one-dalton liabilities that absence has a real cost, because no external standard requires those products to be measured or sets a limit for them.
Material described here is supplied for laboratory use only, and nothing in this guide describes use in a person or an animal.
FOR LABORATORY AND IN-VITRO RESEARCH USE ONLY. NOT FOR HUMAN OR ANIMAL CONSUMPTION. NOT FOR PERSONAL, MEDICAL, DIAGNOSTIC, THERAPEUTIC, OR RECREATIONAL USE.
What is Kisspeptin-10 studied for?
Published research on Kisspeptin-10 investigates the areas below, which is a different question from what Kisspeptin-10 will do for anyone, a claim about a living system that nothing on this site is sold for.
What it is. A man-made peptide ten building blocks long, the tail end of kisspeptin.
What the research looks at. A substantial body of reproductive-hormone research covering the KISS1 receptor and brain-hormone signalling.
How it is thought to work. It works on the KISS1 receptor. Kisspeptin signalling is a well-described part of basic reproductive biology.
What is not established. No approved drug product contains this fragment. The underlying biology being well described is a statement about the field, not about anything in a vial.
The full record, including the certificate for the lot in stock, is on the Kisspeptin-10 product page.
Common questions
What molecular mass should a Kisspeptin-10 certificate show?
Why do two asparagines matter?
How many ways can this peptide gain one dalton?
Would a purity figure catch those changes?
What do the tryptophan and tyrosine add?
More documentation guides
Sources
- PubChem Compound Summary for CID 25240297, Kisspeptin-10. The openable record giving the molecular formula C63H83N17O14 and average mass near 1302.4, and showing the asparagine residues and terminal amide this page turns on.
- ICH Q2(R2), Validation of Analytical Procedures . Defines specificity, including that a method must separate the target from closely related substances, which here means three products each one dalton heavier.
- FDA guidance, Q6B Specifications: Test Procedures and Acceptance Criteria. Sets out how deamidated forms and other named degradation products are specified and reported separately from total purity.
- Finnrick independent verification portal. Third-party lookup used to confirm a certificate resolves to the lot it claims to describe, rather than confirming a document with the seller who supplied it.
