Everything you need to know
Testing is destructive for the portion analysed. Plan the material before you ship rather than after, because a single vial does not always stretch across a full panel and an archival retain.
How much peptide does a lab need for testing?
For purity and identity together, Prodigy typically needs 5 to 20 mg. The range depends on the peptide, the concentration the method runs at, and whether identity is by co-injection or by intact mass. Panels that add endotoxin, bioburden, heavy metals or sterility need additional material and separate aliquots, because those assays cannot be run on the same prepared solution as the chromatography. Confirm the requirement for your exact panel before you open anything. Send the vial sealed where you can, because content can only be reported as mg per vial if the whole vial is reconstituted and weighed.
Do I get the vial back after testing?
Not the portion that was analysed. That material is consumed, and no laboratory can return it. Unused remainder can sometimes be returned by prior arrangement, but it has to be agreed before work starts rather than requested afterwards, because the sample may have been fully prepared by then. If you have exactly one vial and you need both a full panel and a retained sample for later comparison, say so on the intake form. In that situation you usually have to choose, and it is better to make that choice deliberately than to discover it at the end.
Can one vial cover purity, content and endotoxin?
Often yes, if there is enough mass and the split is planned. Endotoxin is a separate assay from chromatography and needs its own aliquot handled with endotoxin-free consumables from the first transfer, otherwise contamination introduced during sampling is indistinguishable from contamination in the product. For a typical 50 mg research vial there is normally enough material for chromatographic work and a separate endotoxin aliquot. Ask for the split plan up front. Why endotoxin is a separate question from purity.
What happens if I send less than the lab needs?
Usually one of three things. The laboratory runs a reduced panel and tells you which results it could not produce, it asks you to send more material and the clock restarts, or it runs the method at a lower concentration and the reporting limits move, which matters most for trace assays. None of these is a disaster but all of them cost time. A short message before shipping avoids all three.
What should I put on the intake form?
Compound name or sequence, the amount stated on the label, the assays you want, and the mass you actually have. If the label amount is uncertain or the vial is unlabelled, say so rather than guessing, because content is reported against the label claim and a wrong claim produces a meaningless percentage. If you need the remainder returned, or you need an archival retain held, ask before work starts. Full submission instructions.