Melanotan 1 20mg — Vial Spec, Reconstitution Math & COA

Overview of Melanotan 1 20mg Laboratory Specifications

A 20mg unit of Melanotan 1 (Afamelanotide / [Nle4, D-Phe7]-α-MSH) represents a high-density cake of lyophilized peptide formulated specifically for institutional laboratory applications. Melanotan 1 is a synthetic peptide structural derivative of endogenous alpha-melanocyte-stimulating hormone (α-MSH). In preclinical models, this peptide functions as a potent, non-selective melanocortin receptor agonist, exhibiting primary affinity for the melanocortin-1 receptor (MC1R). Research laboratories frequently utilize this compound to investigate melanogenesis pathways, skin pigmentation responses, cellular photoprotection mechanisms, and receptor-ligand interaction kinetics.

The 20mg vial configuration is primarily ordered by research groups running large-scale cell culture assays, automated liquid handling systems, or long-term longitudinal animal studies requiring consistent reagent baseline parameters. By utilizing a single 20mg vial rather than multiple smaller units, research teams reduce batch-to-batch variation, simplify inventory control, and streamline high-volume serial dilutions. Each unit undergoes strict lyophilization under inert gas to maintain structural integrity and prevent premature hydrolysis during storage.

PX1 Catalog Availability & Mass Format Guidance

To maintain optimal peptide stability and supply flexibility, PX1 Research stocks the standardized Melanotan 1 10mg vial as our core catalog offering. For laboratories requiring a 20mg target mass, research teams typically procure multiple 10mg units or submit a custom synthesis request through our institutional account portal. You can explore our complete inventory of analytical-grade reagents in the all peptides catalog.

Whether utilizing two 10mg units or a specialized 20mg vial, the chemical composition, purity parameters, and sequence verification remain identical. Both mass formats are synthesized under cGMP-compliant conditions, purified via reverse-phase high-performance liquid chromatography (RP-HPLC), and verified by electrospray ionization mass spectrometry (ESI-MS). The calculations and storage guidelines detailed throughout this technical documentation apply directly to any 20mg total mass requirement.

Molecular Structure and Melanocortin Receptor Profiling

Melanotan 1 is a tridecapeptide with the amino acid sequence Ac-Ser-Tyr-Ser-Nle-Glu-His-D-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2 and a molecular weight of approximately 1646.85 g/mol. As a melanocortin analog, its structure features two key amino acid substitutions relative to wild-type α-MSH: a norleucine (Nle) residue at position 4 and a D-phenylalanine (D-Phe) residue at position 7. These modifications significantly enhance resistance to enzymatic cleavage by central and peripheral endopeptidases, resulting in an extended biological half-life in laboratory models.

Preclinical studies suggest that Melanotan 1 acts as a full agonist across multiple melanocortin receptor subtypes, including MC1R, MC3R, MC4R, and MC5R, with its highest potency directed toward MC1R expressed on cutaneous melanocytes. In vitro assay data indicate that binding to MC1R activates membrane-bound adenylyl cyclase, initiating an intracellular cyclic adenosine monophosphate (cAMP) cascade. This signal transduction pathway upregulates microphthalmia-associated transcription factor (MITF), driving the transcription of tyrosinase and related enzymes responsible for eumelanin synthesis. Researchers evaluate these mechanisms to characterize receptor signaling dynamics, skin pigmentation responses, and repair responses following ultraviolet radiation exposure.

Reconstitution Mathematics for 20mg Lyophilized Vials

Accurate reconstitution of a 20mg Melanotan 1 vial is critical for achieving target working concentrations in cell culture media or assay buffers. The physical mass of the lyophilized cake requires appropriate diluent volumes (such as Bacteriostatic Water or Sterile 0.9% Sodium Chloride) to reach complete dissolution without exceeding target volumetric limits.

To calculate working stock concentrations for a 20mg vial, utilize the following volumetric additions: - Addition of 1.0 mL diluent yields a final concentration of 20.0 mg/mL (20.0 µg/µL). - Addition of 2.0 mL diluent yields a final concentration of 10.0 mg/mL (10.0 µg/µL). - Addition of 3.0 mL diluent yields a final concentration of 6.67 mg/mL (6.67 µg/µL). - Addition of 4.0 mL diluent yields a final concentration of 5.0 mg/mL (5.0 µg/µL).

When performing secondary dilutions for micro-molar or nano-molar cell assays, researchers can utilize our interactive reconstitution calculator to determine precise pipette volumes and dilution factors for automated liquid handling platforms.

Aliquot Planning & Dilution Strategies for In Vitro Assays

Because reconstituted peptides are subject to degradation over extended timeframes, establishing an efficient aliquot protocol immediately following solvent addition is recommended. Repeated freeze-thaw cycles disrupt the tertiary structure and peptide bonds, leading to aggregation or loss of biological activity in downstream assays.

For standard benchtop protocols, after complete dissolution in sterile diluent, the 20mg stock solution should be subdivided into single-use microcentrifuge tubes (e.g., 50 µL to 200 µL per vial). These aliquots should be flash-frozen using liquid nitrogen or a dry ice/ethanol bath and stored at -20°C or -80°C. When an assay is scheduled, individual working aliquots are thawed on ice and diluted directly into assay buffer immediately prior to plate seeding. This practice ensures maximum biological stability and cross-plate experimental consistency.

Comparative Class Analysis: Melanotan 1 vs. Related Melanocortin Compounds

Within melanocortin peptide research, Melanotan 1 is evaluated alongside several structural derivatives and selective receptor ligands. Comparing these compounds highlights key differences in receptor selectivity, structural conformation, and biological targets across preclinical models.

While Melanotan 1 retains a linear peptide backbone optimized for MC1R binding and melanogenesis research, Melanotan 2 is a lactam-bridged cyclic analog that exhibits truncated sequence architecture and enhanced blood-brain barrier permeability in rodent models. Conversely, PT-141 (Bremelanotide) is a active metabolite derivative of Melanotan 2 engineered specifically for central MC3R and MC4R receptor binding pathways. While Melanotan 1 is primarily researched for skin pigmentation responses and photoprotective cellular pathways, cyclic analogs like MT-2 and PT-141 are predominantly investigated for central nervous system and metabolic signaling. Understanding these structural variations allows researchers to select the exact melanocortin agonist best suited to their target tissue assay.

Analytical Verification: HPLC, Mass Spectrometry, and COA Standards

To ensure high experimental reproducibility, every lot of Melanotan 1 synthesized for PX1 Research undergoes rigorous analytical testing prior to vialing. Quality control standards require a minimum chemical purity of ≥98.0% as determined by high-performance liquid chromatography (HPLC). Peak integration analysis confirms the absence of truncated sequences, deletion peptides, or residual counter-ions.

In addition to purity testing, mass identity is verified using Electrospray Ionization Mass Spectrometry (ESI-MS) to confirm the observed molecular weight matches the theoretical value of 1646.85 Da. Crucially, every batch undergoes chromogenic LAL testing to ensure bacterial endotoxin levels remain below strict institutional thresholds (<0.01 EU/µg). Research facilities can review and download lot-matched documentation via our central Certificate of Analysis library.

Thermal Stability, Light Protection, and Reagent Storage Protocol

Lyophilized Melanotan 1 exhibits high physical stability when preserved under controlled environmental conditions. Upon receipt, unopened lyophilized 20mg vials should be stored at -20°C for short-to-medium term storage (up to 12 months) or at -80°C for extended archival storage. Vials must be protected from direct light exposure, as tryptophan and tyrosine residues within the peptide chain are sensitive to UV-induced photo-oxidation.

Once reconstituted with a sterile, preserved diluent (such as 0.9% benzyl alcohol bacteriostatic water), working solutions may be stored at 2°C to 8°C for up to 28 days. Unpreserved aqueous solutions must be used within 24 hours or immediately aliquoted and frozen. Prior to reconstitution, vials stored at sub-zero temperatures should be allowed to equilibrate to room temperature for 15–30 minutes to prevent moisture condensation inside the container upon stopper removal.

Optimizing Mass Procurement: 10mg vs. 20mg vs. Bulk Sourcing

Selecting the correct vial size depends entirely on assay throughput, project duration, and stability constraints. Purchasing a single 20mg total mass format provides cost and workflow efficiencies for high-volume screening protocols where large quantities of standardized stock solution are required across concurrent microtiter plates.

However, for smaller exploratory studies or infrequent assay runs, procuring standard 10mg vials (Melanotan 1 10mg) is often preferred to minimize wasted reagent and avoid prolonged storage of reconstituted liquids. Institutional laboratories planning multi-gram studies or custom vialing specifications can coordinate specialized orders directly through our wholesale laboratory portal. For broader background on melanocortin receptor mapping and experimental assay design, explore the PX1 peptide research hub.