ARA-290 (Cibinetide) is an 11-amino-acid peptide derived from the helix B domain of erythropoietin, specifically engineered to target the innate repair receptor without stimulating hematopoiesis. PX1 Research supplies lab-tested ARA-290 accompanied by lot-specific analytical documentation to ensure reproducible experimental outcomes across preclinical tissue-protection and inflammatory-signaling models.
ARA-290 (Cibinetide) is an 11-amino-acid peptide derived from the helix B domain of erythropoietin, specifically engineered to target the innate repair receptor without stimulating hematopoiesis. PX1 Research supplies lab-tested ARA-290 accompanied by lot-specific analytical documentation to ensure reproducible experimental outcomes across preclinical tissue-protection and inflammatory-signaling models.
Lab-tested ARA-290 refers to high-purity Cibinetide peptide (an 11-amino-acid erythropoietin derivative) that has undergone rigorous analytical validation—including Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) for purity determination, Electrospray Ionization Mass Spectrometry (ESI-MS) for structural identity verification, and Chromogenic LAL testing for bacterial endotoxin quantification prior to laboratory research use.
In experimental biology, utilizing unverified or raw peptide material introduces significant confounding variables. Contaminants such as truncated peptide sequences, residual cleavage reagents (e.g., trifluoroacetic acid), or heavy metals can compromise cellular assays, skew binding affinity measurements, and alter inflammatory cytokine responses in vitro. A fully validated, lab-tested ARA-290 peptide guarantees that chemical identity, sequence fidelity, and precise concentration parameters are established before reconstituting the compound for benchtop protocols.
Researchers evaluating our full catalog of research peptides require absolute transparency regarding lot purity. Independent verification ensures that observed biological activity—such as innate repair receptor engagement or nuclear factor kappa B (NF-κB) attenuation—can be attributed solely to the active ARA-290 sequence rather than synthesis artifacts.
ARA-290, chemically designated as Cibinetide or pyroglutamate helix B surface peptide (pHBSP), is a synthetic 11-amino-acid peptide (sequence: Pyroglutamate-Glutamate-Histidine-Serine-Glutamine-Aspartate-Threonine-Aspartate-Lysine-Arginine-Glycine). It was rationally designed based on the spatial conformation of the aqueous-exposed helix B domain of human erythropoietin (EPO). While native EPO exhibits both hematopoietic and tissue-protective properties, ARA-290 selectively retains tissue-protective signaling while lacking any affinity for the classical homodimeric erythropoietin receptor (EPOR2).
Because it does not bind to the homodimeric EPO receptor, ARA-290 does not stimulate erythropoiesis, reticulocytosis, or changes in hematocrit during preclinical evaluations. This structural selectivity makes it a specialized tool for investigators studying isolated non-hematopoietic pathways. In-depth structural literature available in our PX1 Research Hub details how the helix B peptide motif folds to fit the specific binding pocket of the heteroreceptor complex.
Synthesized via solid-phase peptide synthesis (SPPS), the primary sequence requires precise N-terminal cyclization to form the pyroglutamyl residue. Analytical laboratories must employ specialized chromatographic protocols to differentiate fully cyclized ARA-290 from uncyclized synthetic intermediates, ensuring exact molecular weight matches during mass spectral evaluation.
The primary biological target of ARA-290 is the heterodimeric Innate Repair Receptor (IRR), a protein complex composed of one erythropoietin receptor (EPOR) subunit and one common beta chain (CD131 / CSF2RB) subunit. The IRR is typically expressed at low basal levels in quiescent somatic tissues but undergoes rapid upregulation on parenchymal, endothelial, and immune cells following cellular stress, mechanical injury, or exposure to pro-inflammatory cytokines.
Preclinical studies suggest that when ARA-290 selectively binds to the IRR, it triggers intracellular signaling cascades distinct from the classical JAK2/STAT5 hematopoietic cascade. Instead, IRR activation initiates downstream phosphorylation pathways that modulate the activation of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinases (MAPK). This signaling bias leads to a reduction in the transcription of pro-inflammatory cytokines, including TNF-alpha, IL-1beta, and IL-6.
Furthermore, in vitro data indicate that IRR engagement by erythropoietin-derived peptides promotes anti-apoptotic signaling pathways through Akt activation, preserving mitochondrial membrane integrity during hypoxic or oxidative challenge. Understanding these receptor dynamics requires pristine, lab-tested compounds to avoid off-target signal activation caused by synthesis impurities.
Academic literature has extensively examined ARA-290 across diverse animal models of tissue injury and chronic inflammatory stress. In rodent models of peripheral neuropathy and metabolic dysfunction, administration of ARA-290 was observed to attenuate neuroinflammatory cascades, preserve intraepidermal nerve fiber density, and reduce mechanical allodynia without altering baseline physiological blood parameters.
In models evaluating ischemia-reperfusion injury—such as renal, cardiac, and hepatic vascular occlusion studies—preclinical data indicate that ARA-290 suppresses localized neutrophil infiltration, limits microvascular permeability, and reduces tissue necrosis markers. The peptide’s ability to selectively suppress pro-inflammatory signaling without triggering red blood cell proliferation provides a clean model for dissecting tissue preservation pathways.
Additional research explores ARA-290 in ocular inflammation and microvascular damage assays. Rodent studies investigating diabetic retinopathy and corneal wound healing suggest that IRR stimulation by ARA-290 accelerates re-epithelialization and stabilizes endothelial tight junctions. These preclinical findings underscore the peptide's utility as a probe for innate repair receptor research.
When designing preclinical protocols focused on cellular recovery, inflammation modulation, and tissue protection, investigators often evaluate several candidate peptides side by side. While ARA-290 operates via the heterodimeric EPOR/CD131 complex, other compounds target distinct cellular pathways to achieve complementary biological outcomes.
For example, BPC-157 peptide is a pentadecapeptide derived from human gastric juice studied primarily for its effects on VEGFR2 expression, focal adhesion kinase phosphorylation, and nitric oxide pathway modulation. In contrast, KPV peptide, a C-terminal tripeptide fragment of alpha-MSH, functions predominantly through direct interaction with intracellular inflammatory targets and translocation inhibition of NF-κB. Additionally, TB-500 synthetic peptide acts via actin sequestration (through the LKKTET motif) to influence cell migration and cytoskeletal remodeling. Evaluating these compounds alongside ARA-290 allows researchers to isolate specific receptor-mediated mechanisms versus structural cell matrix responses.
To ensure experimental repeatability, PX1 Research subjects every synthesis lot of ARA-290 to a rigorous analytical battery within an ISO 17025 accredited laboratory environment. Verifying a peptide's physical and chemical parameters requires multiple orthogonal testing methods:
1. Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC): RP-HPLC separates the target peptide from related impurities, deletion sequences, and side-reaction products based on hydrophobicity. Chromatographic purity for PX1 ARA-290 must routinely exceed 98.0% peak area integration. 2. Electrospray Ionization Mass Spectrometry (ESI-MS): ESI-MS verifies exact molecular mass (theoretical monoisotopic mass ~1257.3 Da), confirming sequence identity and checking for incorrect amino acid additions or missing protecting groups. 3. Endotoxin Testing (LAL Assay): Bacterial endotoxins (lipopolysaccharides) can confound inflammatory cytokine assays. PX1 verifies that endotoxin levels remain strictly below <0.1 EU/mg using Chromogenic Reagent LAL methods. 4. Residual Solvent and Moisture Analysis: Volatiles such as acetonitrile, trifluoroacetic acid (TFA), and residual water are quantified to ensure stability and precise mass determination during reconstitution.
Proper handling and reconstitution protocols are vital to preserve the structural integrity of ARA-290 during benchtop research. Because lyophilized peptides are sensitive to humidity and temperature fluctuations, vials should be allowed to equilibrate to room temperature inside a desiccator prior to opening.
Reconstitution should be performed using sterile, laboratory-grade solvents such as Bacteriostatic Water (0.9% benzyl alcohol) or sterile phosphate-buffered saline (PBS, pH 7.4), depending on the requirements of the downstream assay. Solvent should be added down the side of the glass vial wall, followed by gentle swirling or inversion. Vortexing or vigorous agitation must be avoided, as high mechanical shear forces can induce peptide aggregation or denaturation.
For cell culture assays sensitive to trace preservatives, sterile 0.9% Sodium Chloride or standard culture media may be utilized immediately prior to application. If establishing a bulk lab account for high-throughput screening, researchers should establish consistent reconstitution SOPs across all laboratory technicians to maintain inter-assay consistency.
Lyophilized ARA-290 exhibits excellent long-term stability when stored under controlled environment conditions. Sealed vials should be stored at -20°C or -80°C in a frost-free freezer, protected from light exposure, where they remain stable for up to 24 months from the date of manufacture.
Once reconstituted into aqueous solution, the peptide's shelf life decreases due to potential hydrolysis and oxidation pathways. Reconstituted stock solutions should be aliquoted into single-use polypropylene microcentrifuge tubes to prevent repeated freeze-thaw cycles. Reconstituted aliquots stored at 2°C to 8°C should generally be utilized within 7 to 14 days, whereas aliquots frozen at -20°C remain viable for up to 3 to 6 months.
Primary chemical degradation pathways for ARA-290 include deamidation at asparagine/glutamine residues and oxidation of histidine residues when exposed to ambient light and dissolved oxygen. Storing stock aliquots under inert gas (e.g., nitrogen overlay) and using light-blocking amber microcentrifuge tubes further mitigates these degradation risks.
PX1 Research is dedicated to supplying the scientific community with USA-manufactured research peptides manufactured under strict GMP-compliant quality management systems. Every batch of ARA-290 undergoes rigorous quality control to ensure batch-to-batch consistency and absolute analytical purity.
When purchasing from PX1 Research, laboratory investigators receive comprehensive, lot-specific Certificates of Analysis (COAs) detailing raw HPLC chromatograms, mass spectra, residual solvent levels, and endotoxin scores. We maintain full lot traceability from raw amino acid precursor sourcing through final lyophilization and vial sealing.
To support fast-paced research schedules, PX1 Research provides same-day shipping (Monday through Friday) operating directly out of our centralized distribution centers in California and Arizona. This infrastructure ensures rapid delivery while maintaining optimal cold-chain logistics for temperature-sensitive reagents.
What is the primary mechanism of action of ARA-290?
ARA-290 selectively binds to the heterodimeric Innate Repair Receptor (IRR), composed of EPOR and CD131 subunits. This triggers anti-inflammatory and tissue-protective signaling cascades without binding to the classical EPOR homodimer or stimulating erythropoiesis.
How is the purity of PX1 Research ARA-290 verified?
Every lot of PX1 Research ARA-290 undergoes Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) for purity determination, Electrospray Ionization Mass Spectrometry (ESI-MS) for mass identity verification, and Chromogenic LAL testing to confirm endotoxin levels are <0.1 EU/mg.
Does ARA-290 stimulate red blood cell production in preclinical models?
No. Preclinical literature confirms that ARA-290 lacks affinity for the homodimeric EPO receptor (EPOR2), meaning it does not stimulate erythropoiesis, alter hematocrit, or increase red blood cell counts during laboratory studies.
What solvent is recommended for reconstituting ARA-290 in the lab?
ARA-290 is readily soluble in sterile Bacteriostatic Water, 0.9% Normal Saline, or Phosphate-Buffered Saline (PBS, pH 7.4). Solvents should be selected based on the specific requirements of the downstream in vitro or preclinical assay.
What is the recommended long-term storage condition for lyophilized ARA-290?
Lyophilized ARA-290 should be stored at -20°C or -80°C in a desiccated environment protected from direct light. Under these conditions, the unconstituted peptide remains stable for up to 24 months.
How should reconstituted ARA-290 stock solutions be handled to avoid degradation?
Reconstituted solutions should be divided into single-use aliquots and stored at -20°C to minimize degradation from repeated freeze-thaw cycles. Aliquots stored at 2–8°C should be used within 7–14 days.
What is the molecular weight of ARA-290?
ARA-290 (Cibinetide) has a molecular mass of approximately 1257.3 Da, corresponding to its 11-amino-acid sequence with an N-terminal pyroglutamyl modification.
Where are PX1 Research peptides manufactured and shipped from?
All PX1 Research compounds are manufactured in US-based GMP-compliant facilities and shipped directly from our state-of-the-art logistics hubs in California and Arizona with same-day shipping on orders placed Monday through Friday.
All products are sold strictly for laboratory and research use only. Not for human or veterinary use, diagnosis, treatment or consumption. Statements have not been evaluated by the FDA.