What an identity test answers
A peptide can be perfectly pure and still be the wrong peptide. Purity tells you how much of the vial is one compound; only a mass measurement tells you which compound it is. Every so often mass spectrometry finds a molecule with nothing to do with the label at all, and nothing short of measuring the mass would have caught it.
Identity is the first question for any research sample, which is why it is in every package.
How we run it
Identity runs on liquid chromatography–mass spectrometry with electrospray ionization (LC-MS, ESI). The observed mass is compared with the theoretical mass of the compound you declare. Where a sample ionizes poorly, MALDI-TOF is used for confirmation.
Every batch runs alongside blanks and system suitability injections. If the system does not pass, your sample does not run: we would rather tell you about a one-day delay than release a number we do not trust.
What the certificate reports
- Observed versus theoretical mass
- The mass error in ppm
- A pass or fail identity call in plain language
- Method, instrument conditions and the named analyst
- A COA number anyone can check at Verify a COA
How to order
- Create a free account. Individual or business; an individual account needs only an email address.
- Build the order and submit it. One row per sample. Choose a package that includes identity, or add it to any sample.
- Get your chain-of-custody form and payment link. Both are emailed the moment you submit and saved on the order in your account.
- Post the vials. Write each Sample ID on its vial and on the package, and add your tracking number to the order.
Sample requirements
For lyophilized powder, 2 mg or more per vial is ideal; we can usually work with less and will tell you before we start if the amount is marginal. For reconstituted solution, send at least 0.5 mL. This test is subdivided from the same vial as the sample’s other tests. Pro 7X takes two vials of the same sample, because it includes sterility.
Questions
Does an identity pass mean the peptide is pure?
No. Identity confirms which molecule is present; it says nothing about how much else is in the vial. Purity by HPLC answers that, and the Starter package runs both on the same sample for less than ordering them separately.
What do I need to tell you?
The compound name exactly as it appears on the label, and the amount in the vial in mg. The observed mass is compared against that compound, so the name you give is the claim being tested.
What if the result is ambiguous?
The certificate says so. A borderline measurement is reported as borderline; it is never rounded into a pass.