What is P21?
P21 (CNTF-derived neuroprotective tetrapeptide) is a 4-amino acid CNTF-derived peptide. Synthetic tetrapeptide derived from ciliary neurotrophic factor (CNTF) activating CNTF receptor (CNTFRα) complex and downstream JAK-STAT3 signalling. Promotes neuronal survival, reduces neuroinflammation, and supports neural progenitor cell activity in CNS injury and neurodegeneration models.
Research Applications
CNTF Receptor Activation
CNTFRα complex binding and JAK-STAT3 pathway research
Neuronal Survival
Anti-apoptotic neuroprotection in ischemia and excitotoxicity models
Neural Progenitor Biology
Proliferation and differentiation of neural progenitor cells
Neuroinflammation
Microglia and astrocyte modulation, inflammatory cytokine reduction
vs Full CNTF
Minimal active fragment potency and CNS penetration comparison
Quick Specs
| Form |
Sequence-specific (human p21 protein ~164 amino ac |
| Purity |
≥99% by HPLC — every batch |
| CAS Number |
9001-37-0 (for recombinant forms; sequence-depende |
| Molecular Weight |
MS molecular weight confirmed — every batch |
| Specification |
≥99% by HPLC — every batch |
| Shelf Life |
24 months unopened |
| Storage |
-20°C sealed | 2–8°C reconstituted (2–4 weeks) |
| Manufacture |
In-house Fmoc SPPS — Qingdao, China |
| Brand |
Asia |
Certificate of Analysis (COA)
Frequently Asked Questions
How do I reconstitute this peptide?
Add 1–2mL bacteriostatic water to the lyophilized vial by directing water down the inner wall of the vial. Swirl gently until the powder fully dissolves — do not shake or vortex. The solution should be clear and colourless. Use immediately or refrigerate at 2–8°C.
How should this peptide be stored?
Store lyophilized peptide vials at −20°C for long-term storage. Once reconstituted, store at 2–8°C (refrigerator) and use within 21–28 days. Avoid repeated freeze-thaw cycles, direct light, and heat exposure.
What purity is this QSC compound and how is it verified?
All QSC compounds are tested to ≥99% purity by HPLC peak area analysis on every production batch. Molecular identity is confirmed by mass spectrometry. A Certificate of Analysis (COA) is published on the product page and independently verifiable at verify.janoshik.com using the batch reference number.
🧪 Peptide Research Tools: Use QSC's free
peptide calculators — reconstitution, BAC water, dosing, half-life, and mixing charts.
🌍 Domestic shipping: 🇺🇸 USA 5–7 days
🌏 International shipping: 7–14 days
⚠️ RESEARCH USE ONLY — NOT FOR HUMAN CONSUMPTION
QSC products are strictly for in vitro and in vivo laboratory research.
Safety & Handling
🚫
Not for Human Use
These compounds are for research only.
🥽
PPE Required
Always use appropriate protective equipment.
❄️
Storage Compliance
Follow product-specific storage conditions.
Product-Specific Storage
-20°C sealed | 2–8°C reconstituted (2–4 weeks)
