Selank 20mg — Vial Spec, Reconstitution Math & COA

Overview of Selank 20mg Vial Specifications and Catalog Status

Selank is a synthetic heptapeptide derivative of the naturally occurring human immunomodulatory peptide Tuftsin, engineered with a Pro-Gly-Pro sequence at its C-terminus to enhance metabolic stability against enzymatic cleavage. In academic and institutional laboratory settings, high-mass formats such as the Selank 20mg vial are selected primarily for high-throughput screening, multi-plate enzyme assays, or extended preclinical animal model series where maintaining batch consistency across all working replicates is essential.

To ensure precise resource planning, research teams should note that PX1 Research maintains high-purity stock across standard and high-yield sizes. While custom high-mass lots like 20mg are processed for specialized bulk research accounts, our catalog stock standard relies on the optimized Selank 10mg vial to minimize reconstituted freeze-thaw cycles and thermal degradation risk. Principal investigators can review our full inventory across all analytical classes via the main all peptides catalog. Regardless of mass specification, all PX1 Research compounds are synthesized under strict quality controls for solid-phase peptide synthesis (SPPS).

Chemical Identification and Structural Architecture

Selank possesses the chemical sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro (Thr-Lys-Pro-Arg-Pro-Gly-Pro, CAS No. 129954-34-3) with a molecular formula of C33H57N11O9 and a exact molecular weight of 751.9 g/mol. The incorporation of the C-terminal tripeptide Pro-Gly-Pro extends its biological half-life in extracellular environments compared to its parent sequence, native Tuftsin, by resisting carboxypeptidase and aminopeptidase degradation.

In vitro analytical studies demonstrate that the structural stability of Selank relies heavily on maintaining a stable ionic environment during reconstitution. The polar, basic residues (Threonine, Lysine, Arginine) render the lyophilized cake highly soluble in aqueous buffer systems, but also sensitive to alkaline hydrolysis if stored at elevated pH levels. Understanding these primary sequence dynamics allows researchers to select appropriate reconstituting vehicles and maintain working solutions without premature peptide fragmentation.

Reconstitution Mathematics for 20mg Lyophilized Formulations

Reconstitution calculations for a high-density 20mg lyophilized cake require strict attention to final concentration requirements, meniscus displacement, and working pipette volume ranges. Adding smaller diluent volumes yields high stock concentrations useful for master stock preparations, whereas larger volumes dilute the peptide to workably measurable microliter aliquots for microplate assays.

When preparing a 20mg Selank vial, the final concentration ($C$) is calculated as total mass ($M = 20\text{ mg} = 20,000\text{ }μ\text{g}$) divided by added diluent volume ($V$). Consider the following standardized dilution setups:

• 1.0 mL Diluent Addition: Yields a concentration of 20.0 mg/mL (20.0 μg/μL). A standard 10 μL liquid transfer delivers exactly 200 μg of target compound.

• 2.0 mL Diluent Addition: Yields a concentration of 10.0 mg/mL (10.0 μg/μL). A 10 μL transfer delivers 100 μg of target compound.

• 3.0 mL Diluent Addition: Yields a concentration of 6.67 mg/mL (6.67 μg/μL). A 10 μL transfer delivers 66.7 μg of target compound.

• 4.0 mL Diluent Addition: Yields a concentration of 5.0 mg/mL (5.0 μg/μL). A 10 μL transfer delivers 50 μg of target compound.

To quickly recalculate customized dilution protocols, stock concentrations, or volumetric draw targets for various lab assays, researchers are encouraged to use the PX1 Research interactive reconstitution calculator.

Aliquot Planning and Dilution Workflows for Laboratory Assays

Handling a 20mg mass in a single vial introduces technical challenges regarding storage stability after initial rubber stopper puncture. Once reconstituted in bacteriostatic water (0.9% benzyl alcohol) or sterile normal saline (0.9% NaCl), repeated access to the primary vial increases risks of atmospheric oxidation and bacterial contamination.

For optimal bench efficiency, laboratory protocols should mandate immediate aliquot partitioning post-reconstitution. Using sterile, polypropylene low-binding microcentrifuge tubes, the primary master stock should be divided into single-use sub-aliquots (e.g., 100 μL to 250 μL per tube) and immediately frozen. This process eliminates repeated freeze-thaw cycles—a primary cause of peptide peptide bond cleavage and aggregation—ensuring that every microplate assay or cell culture model receives uniform compound potency.

Storage Parameters and Degradation Kinetics

Lyophilized Selank 20mg vials maintain maximal stability when stored in dark, desiccated environments at -20°C to -80°C. In un-reconstituted dry powder form, the compound remains stable for up to 24 months under these deep-freeze conditions. Exposure to ambient room temperature, direct ultraviolet light, or high humidity should be minimized during initial lab inventory check-in.

Following reconstitution with appropriate diluents (such as bacteriostatic water), liquid working solutions should be stored at 2°C to 8°C and utilized within 21 to 28 days. If prepared using sterile water for injection without preservatives, reconstituted solutions must be used within 24 to 48 hours or aliquoted and frozen at -80°C. Preclinical data indicate that freezing liquid aliquots below -20°C preserves structural integrity for up to 6 months, provided frost-free freezer cycles are strictly avoided.

Lot-Matched Certificate of Analysis (COA) and Quality Verification

Every production lot of Selank distributed by PX1 Research undergoes rigorous independent analytical verification. We provide a downloadable, lot-matched Certificate of Analysis (COA) for every fill size, verifying both chemical identity and purity via High-Performance Liquid Chromatography (HPLC) and Mass Spectrometry (MS).

To access lot-specific analytical reports, researchers can visit our centralized COA verification hub. Quality parameters verified for every batch include:

• Purity Threshold: $\ge 98.0\%$ verified by reverse-phase HPLC peak area integration.

• Molecular Weight Confirmation: Electrospray Ionization Mass Spectrometry (ESI-MS) confirming identity within $\pm 1.0\text{ Da}$ of theoretical 751.9 Da.

• Endotoxin Quantitation: Chromogenic LAL testing ensuring endotoxin levels remain below strict threshold limits ($<0.05\text{ EU/mg}$) for sensitive cell culture assays.

• Counterion Content & Residual Solvents: Gas chromatography and ion chromatography to confirm acceptable trifluoroacetate (TFA) removal.

Comparative Analysis: Selank vs. Semax and Related Neuroactive Peptides

When designing preclinical protocols investigating central nervous system signaling pathways, researchers frequently compare Selank against other synthetic regulatory peptides. While Selank is derived from Tuftsin and studied primarily for its interactions with GABAergic systems, brain-derived neurotrophic factor (BDNF) expression, and immune-neural cross-talk, related peptides utilize distinct signaling cascades.

For instance, Semax is an ACTH(4-10) analogue that acts predominantly through melanocortin receptor activation and neurotrophin upregulation. Researchers exploring modified kinetics often evaluate stabilized derivatives like N-Acetyl Semax Amidate alongside Selank to evaluate comparative enzymatic degradation rates in tissue homogenates. Furthermore, novel central research tools like PE22-28 target potassium channel pathways (TREK-1), offering an alternative mechanistic benchmark for preclinical neurochemical screens.

Selecting Vial Mass: 10mg vs. 20mg Formulations for Lab Protocols

Selecting between a 10mg and a 20mg vial configuration depends on the scope of the planned experimental matrix. High-mass 20mg vials provide volumetric efficiency and cost-effectiveness when running simultaneous, high-density cell viability assays, automated robotic liquid handling sequences, or large rodent cohort studies where dilution volumes are consumed rapidly.

Conversely, for pilot studies, exploratory dosage-response curves, or assays spaced weeks apart, ordering standard Selank 10mg vials is generally advantageous. Smaller mass units reduce the total time a reconstituted compound remains in aqueous solution, thereby mitigating the risk of gradual hydrolysis or potency loss over extended research timelines. Institutional buyers seeking large-scale custom runs or multi-vial bulk configurations can coordinate directly with our team through the PX1 Research wholesale platform.

Procurement Integrity and USA Manufacturing Standards

PX1 Research enforces strict manufacturing and distribution standards to guarantee batch-to-batch reproducibility for academic and industrial research facilities across the United States. All peptide synthesis is executed in GMP-compliant, ISO 17025 accredited domestic facilities, avoiding the analytical inconsistencies often associated with unverified overseas sourcing.

Orders placed before 12:00 PM PST (Monday through Friday) ship same-day from our primary logistics centers located in California and Arizona. Each shipment includes cold-pack thermal insulation and specialized protective packaging to shield sensitive peptide structures from ambient heat spikes during transit. Researchers looking to explore our broader library of biochemical tools can access comprehensive mechanistic summaries and data sheets through our integrated research hub.