Description
The P21 5mg vial is a laboratory reference material and nothing else. The compound is a synthetic peptidergic compound derived from a CNTF fragment. The fill weight is 5 mg of net peptide content. Appearance is white to off-white, sealed under vacuum, with the lot number printed on the label. It is not a food, not a drug, and not for human or veterinary consumption.
The same material is catalogued elsewhere as P021. The label on the P21 5mg vial carries the compound, the fill weight and the lot number, and that is the extent of it.
What the P21 5mg vial is
Everything that can honestly be said about the P21 5mg vial before the certificate is opened is listed below.
| Specification | As supplied |
|---|---|
| Compound | P21 |
| Vial content | 5 mg net peptide content |
| Form | Lyophilized, white to off-white, sealed under vacuum |
| Sequence length | On the lot certificate |
| Purity | HPLC, percent of total peak area |
| Identity | Mass spectrometry against expected mass |
| Water | Karl Fischer titration, percent by weight |
| Documentation | Independent certificate of analysis, tied to the lot number |
| Price basis | About $35.80 per milligram as priced |
| Supplied for | Laboratory research use only, not for human or veterinary consumption |
Freeze dried powder, fill weight and price per milligram
Freeze drying is how a peptide reaches you stable at ambient temperature. The solution is frozen solid, then the ice is pulled off under vacuum instead of being melted, so the water never passes through a liquid phase on the way out. What is left behind is a porous cake. In the vial it may sit as a flat disc, a loose dust, or a thin film part way up the glass. None of those appearances says anything about the contents. Fill weight and the assay figure do. Nothing about the P21 5mg vial is sold by volume.
The arithmetic
Milligram content is the unit the P21 5mg vial is sold in, because it is the only figure that makes two listings comparable. The quotient is close to $35.80 per milligram. Keep two things in view when you use it: the fill weight it was divided by, and the assay percentage from the certificate, because the second tells you how much of that fill is the named compound. Compare the P21 5mg vial on that basis rather than on the price of the glass. The case is made at greater length in why price per milligram beats the price on the bottle.
What the certificate of analysis reports
Certificates vary in layout and should not vary in content. Compound name, lot number, analysis date, HPLC purity with chromatogram, mass spectrometry identity, water content, laboratory identity and signature. Check the lot number against the vial, check the date, then read the figures. Documents that summarise results without showing the chromatogram are asking for more trust than they have earned. The certificate issued with the P21 5mg vial is specific to the lot and not to the product line.
Assays are run by an outside contract laboratory rather than in house. Independence of that kind matters, and it has a limit: the figure still depends on the sample that was submitted, which is why lot by lot testing rather than periodic testing is the part that matters. Stock is withdrawn from sale where the certificate for the P21 5mg vial does not support the figures here. See how to read a certificate of analysis and why we publish the batch that failed.
Purity, identity and moisture are three different measurements
HPLC provides the purity percentage. The method resolves a mixture into its parts on a column and the detector reports them as peaks whose areas are integrated. Purity is the main peak over the sum of all peaks. Because it is a ratio, two lots can share a purity figure and still differ in fill weight, which is why both numbers are published and neither substitutes for the other. The same methods are run on the P21 5mg vial as on every other lot on this shelf, and formulae and expected masses for compounds of this class can be checked through the NCBI chemistry and literature databases.
Names, abbreviations and how to keep the P21 5mg vial
Abbreviations here are inherited rather than designed. They come from the groups that first made a compound, from ingredient registers, from development programmes and from vendors, so two listings can look different and be identical. CNTF is left as four letters, because the expanded form of the abbreviation describes an activity. The catalogue name carried by the P21 5mg vial is the one the trade uses, and a trade name is not an identifier.
Dry material is forgiving within limits. Refrigeration at 2 to 8 degrees Celsius suits short storage and minus 20 degrees Celsius or lower suits long storage, with light and humidity the two things to keep away from the vial. Keep the certificate with the P21 5mg vial, since the lot number is the only thing joining the two.
What this listing refuses to say
The material is a reagent. It is not a medicine, not a supplement, not for human or veterinary consumption, and it is sold for in vitro and laboratory work by purchasers qualified to handle it. You will not find a dose, a schedule, an injection site or a mixing instruction here. Those belong to a use that is not offered. No part of this page describes a use for this material in a person or an animal. Bacteriostatic water, sterile diluents and syringes are stocked separately rather than sold as a set with the vial.
Two things are true at once. This is sold as a laboratory reference material, and that sentence on its own settles nothing, because a page that describes effects, timing or quantities for a person is describing a use whatever the footer says. See research use only is not a legal strategy.
Read the certificate, check the lot number against the vial, and the listing has told you everything it can tell you. This item sits on the nootropic shelf, inside the research peptide catalogue, and every certificate we hold is on the lab results page.
Reviews
There are no reviews yet.