How Long Does Cartalax Last? Storage Before and After Mixing
Lyophilised Cartalax keeps best sealed, dry and frozen at −20 °C; once mixed with bacteriostatic water it lasts 8 to 12 weeks at 2 to 8 °C under Vistara Labs’ handling guidance, with quality slowly fading from around week 6 to 8. No published stability study or major chemical supplier’s data sheet gives a storage figure for Cartalax, so the after-mixing window is the general peptide guidance. Its three residues, alanine, glutamic acid and aspartic acid, avoid most of the reactive groups that shorten a peptide’s life in solution.
Findings
- Cartalax is the tripeptide Ala-Glu-Asp, formula C12H19N3O8 and molecular weight 333.29, also listed as T-31 (PubChem CID 87815447).
- No compound-specific storage figure was found in the published literature or on a major chemical supplier’s data sheet.
- Its sequence has no methionine, cysteine, tryptophan, asparagine or glutamine, the residues most often behind oxidation and deamidation (Manning et al., Pharm Res, 2010).
- Aspartic acid can isomerise through a ring intermediate, and the residue next to it strongly changes the rate (Geiger and Clarke, J Biol Chem, 1987).
How long does Cartalax powder last?
No chemical supplier data sheet we could open gives a storage figure for Cartalax powder. The nearest comparison is Pinealon, another three-residue peptide from the same research programme, which one supplier rates at 1 year at −20 °C and 2 years at −80 °C as a sealed powder. That is a figure for a different compound, not for Cartalax. The safe practice is the same either way: freezer for long holds, fridge for near-term work. Moisture is the main enemy of a freeze-dried cake, because it lets the same reactions that happen in solution start in the solid. The 20 mg vial is kept capped and boxed, and a cold vial is brought to room temperature before opening so that condensation does not form on the powder.
How long does Cartalax last after mixing?
At 2 to 8 °C, dark and accessed only through a swabbed stopper, mixed Cartalax lasts 8 to 12 weeks, with quality fading from around week 6 to 8. That is the general row in how long peptides last after mixing. The Cartalax reconstitution page has the calculator for the 20 mg vial.
What the sequence says about stability
Nothing has been published on how Cartalax itself breaks down in solution, so the picture comes from what each residue is known to do. It is a short, charged peptide with two acidic side chains, and it has none of the residues behind the commonest fast changes. Methionine and cysteine oxidise, tryptophan oxidises under light, and asparagine and glutamine deamidate (Manning et al., 2010). Cartalax contains none of them.
Aspartic acid is the one residue with a known slow route. It can form a ring intermediate with the backbone of the residue that follows it and reopen as the isomer isoaspartate. In model peptides this ran about 34 times more slowly for aspartic acid than for asparagine, and in an asparagine peptide, swapping the following residue for a bulkier one slowed breakdown 33 to 50-fold (Geiger and Clarke, 1987). In Cartalax the aspartic acid is the last residue, so there is no following residue in the chain; that should make this route less important here, though this is an inference from the chemistry, not a measured result.
Two other points help. The glutamic acid sits in the middle of the chain, not at the start, so the ring closure that turns a starting glutamic acid into pyroglutamic acid (Chelius et al., Anal Chem, 2006) does not apply. And with only three residues, there is no folded shape to lose. The practical result is the general window, kept cold and dark, with no reason to stretch it.
How long does Cartalax last at room temperature?
There is no published figure for Cartalax in solution at room temperature. A mixed vial is taken out of the fridge only for handling, because warmth speeds every slow reaction, including the isomerisation described above.
Can Cartalax be frozen?
The powder can, and the freezer is the right place for long holds. No supplier figure was found for frozen Cartalax solution. A working vial should not be frozen and thawed repeatedly, since freeze-thaw cycles aggregate peptides in solution.
How can you tell mixed Cartalax has degraded?
- Yellowing or any tint. Mixed Cartalax should be clear and colourless.
- Cloudiness that does not clear within 10 to 15 minutes of mixing, or that appears later.
- Particles or sediment.
- Gel or thickening.
Isomerisation is invisible, which is why the time window applies even to a vial that still looks perfect.
Cartalax storage at a glance
| State | Where | How long |
|---|---|---|
| Powder, sealed | −20 °C, dry | No compound-specific figure; long holds |
| Powder, sealed | 2 to 8 °C, fridge | No published figure; near-term only |
| Mixed with bacteriostatic water | 2 to 8 °C, dark | 8 to 12 weeks, fading from week 6 to 8 (store guidance) |
| Mixed, room temperature | Handling only | No published figure |
Certificates of analysis are on the lab reports page, and every order ships from within Canada by Canada Post Xpresspost.
Vistara Labs supplies Cartalax as a laboratory research material. The windows on this page describe how long the peptide stays in good condition.
Frequently asked questions
How long does Cartalax last in the fridge after mixing?
Under Vistara Labs’ handling guidance, 8 to 12 weeks at 2 to 8 °C in the dark, with quality fading from around week 6 to 8.
How long does Cartalax last at room temperature?
No published figure exists for Cartalax in solution at room temperature. A mixed vial is kept in the fridge and taken out only for handling.
Can you freeze Cartalax?
Yes as powder, and the freezer is the place for long holds, although no supplier publishes a Cartalax-specific figure. A working vial of solution should not go through repeated freeze-thaw cycles.
Does Cartalax go bad?
Yes, slowly. It lacks the residues that change fastest in solution, but its aspartic acid can isomerise and warmth speeds every reaction. Cloudiness, particles, a tint or gel mean it has degraded.
Does Cartalax store the same way as Pinealon?
Much the same. Both are three-residue peptides with an aspartic acid, but Pinealon starts with glutamic acid, which can cyclise, while Cartalax starts with alanine, which cannot.
Handling windows: Vistara Labs, October 2026. Sources: PubChem. Alanyl-glutamyl-aspartic acid (Cartalax), CID 87815447: formula, molecular weight and synonyms. PubChem. Manning MC et al. Stability of protein pharmaceuticals: an update. Pharm Res. 2010. PMID 20143256. Geiger T, Clarke S. Deamidation, isomerization, and racemization at asparaginyl and aspartyl residues in peptides. J Biol Chem. 1987. PMID 3805008. Chelius D et al. Formation of pyroglutamic acid from N-terminal glutamic acid in immunoglobulin gamma antibodies. Anal Chem. 2006. PMID 16579622. MedChemExpress. Pinealon, HY-P4052, product data sheet: storage (comparison only). PDF.
More on this: How Long Do Peptides Last After Mixing?
All products supplied by Vistara Labs are intended for laboratory research use only. They are not drugs, are not approved for human or veterinary use, and are not intended to diagnose, treat, cure or prevent any condition. Nothing on this page constitutes medical advice or guidance for use in humans.
