Introduction to Bulk Melanotan II for Research
Melanotan II is a synthetic cyclic heptapeptide analogue of alpha‑melanocyte‑stimulating hormone (α‑MSH). First described in peer‑reviewed literature in the 1990s, it serves as a research tool for investigating melanocortin receptor subtypes, melanogenesis pathways, and related intracellular signalling cascades. Laboratories that study pigmentation biology, neuroendocrine regulation, or cyclic peptide stability routinely require this peptide in consistent, high‑purity batches. For established pharmaceutical and biotech institutions, the decision to buy Melanotan II bulk wholesale is driven by the need for reproducible experimental data and long‑term project continuity.
A reliable bulk supply of this lyophilized peptide allows research groups to perform extensive in‑vitro receptor binding screens, melanin synthesis assays, and conformational analyses without the interruptions caused by variable lot‑to‑lot quality. When sourcing a wholesale partner, academic core facilities and contract research organisations typically evaluate purity analytics, cold‑chain logistics, and the availability of independent certificates of analysis. This article outlines the key specifications, quality‑control benchmarks, order‑logistics considerations, and legitimate laboratory applications that inform a compliant bulk purchase of Melanotan II.
Chemical Composition and Specifications
Melanotan II has the molecular formula C₅₀H₆₉N₁₅O₉ and a monoisotopic mass of approximately 1087.2 Da. Its amino‑acid sequence is Ac‑Nle‑cyclo[Asp‑His‑D‑Phe‑Arg‑Trp‑Lys]‑NH₂. The lactam bridge between the side chains of aspartic acid and lysine confers the cyclic topology that is critical for receptor selectivity in vitro. In powder form, the peptide appears as a white to off‑white lyophilised solid.
Purity and Analytical Standards
Research‑grade Melanotan II is routinely supplied with a purity of ≥98% as determined by reversed‑phase high‑performance liquid chromatography (RP‑HPLC). Impurity profiles, including deletion sequences and diastereomers, are annotated on the batch‑specific certificate of analysis. For advanced studies—such as surface plasmon resonance or isothermal titration calorimetry—some laboratories prefer material exceeding 99% purity, which can often be requested as a custom purification service. Counter‑ion content (typically acetate or trifluoroacetate) is quantified and reported.
Storage and Handling
The lyophilised peptide remains most stable when stored at ‑20°C in a tightly sealed container protected from moisture and light. Under these conditions, manufacturers often guarantee structural integrity for two to three years from the date of synthesis. After reconstitution in sterile buffers (e.g., phosphate‑buffered saline or 10‑mM acetic acid) for in‑vitro assays, the solution should be aliquoted and stored at –80°C to minimise freeze‑thaw degradation. Exposure to room temperature should be limited to the time needed for weighing and dissolution.
Quality Control and Testing Protocols
Reputable suppliers adhere to a multi‑tier quality‑control framework designed to confirm identity, purity, and suitability for biochemical research. The three core analyses are described below.
HPLC Analysis for Purity Assessment
Each bulk lot is subjected to RP‑HPLC with UV detection, typically at 220 nm, to quantify the target peptide and related impurities. A single symmetric peak accounting for ≥98% of total peak area is the industry benchmark. The chromatogram, along with integration data, is included in the certificate of analysis.
Mass Spectrometry for Molecular Weight Confirmation
Electrospray ionisation mass spectrometry (ESI‑MS) or matrix‑assisted laser desorption/ionisation time‑of‑flight (MALDI‑TOF) is used to confirm that the observed mass matches the theoretical value within the instrument’s mass accuracy (usually ±0.5 Da). A representative mass spectrum is archived for every lot and can be shared upon request.
Endotoxin and Residual Solvent Testing
For in‑vitro work—particularly assays involving primary cell cultures or sensitive reporter systems—low endotoxin levels are critical. Bacterial endotoxin is measured by the limulus amebocyte lysate (LAL) method; wholesale shipments typically report < 1 EU/mg. Residual process solvents (e.g., acetonitrile, trifluoroacetic acid) are analysed by gas chromatography (GC) or nuclear magnetic resonance (NMR) and maintained below ICH‑defined thresholds.
Third‑party laboratory verification is available from suppliers who submit blind samples to independent analytical facilities. The resulting reports provide an extra layer of confidence for institutions that require external validation before incorporating a new batch into their research programmes.
Bulk Ordering and Supply Chain Considerations
When preparing to buy Melanotan II bulk wholesale, researchers and procurement officers should align on minimum order quantities, packaging formats, and temperature‑controlled logistics that preserve peptide integrity from synthesis suite to laboratory freezer.
Minimum Order Quantities and Packaging
Bulk orders often start at 1 gram of net peptide content and can be scaled to 10 grams or more. The material is typically dispensed into single‑use borosilicate glass vials sealed under argon or nitrogen to prevent oxidation. For very large quantities (>50 grams), manufacturers may provide the peptide in a single sterile, evacuated container with a PTFE‑lined closure. Each primary container is labelled with the product name, lot number, net weight, and storage instructions.
Cold Chain Shipments
To maintain the recommended storage temperature during transit, bulk shipments are packed in validated thermal containers with sufficient phase‑change gel packs or dry ice to hold ≤–20°C for 48–72 hours. Temperature data loggers placed inside the packaging provide an audit trail that is often shared with the recipient. Freight forwarders experienced in transporting biochemical materials ensure compliance with international regulations, including IATA for air transport.
Lead Times and Customs Clearance
Standard production lead times for bulk peptides range from four to eight weeks, depending on batch size and the purification protocol. Express synthetic routes can shorten this window for an additional fee. Once dispatched, international shipments require customs tariff codes appropriate for “research chemicals” (e.g., HS 3822.00). A detailed commercial invoice, material safety data sheet (MSDS), and a letter of no commercial value intended for laboratory use assist in smooth clearance. Buyers should verify their institution’s import permits for synthetic peptides before placing an order.
Applications in Laboratory Research
Melanotan II is used exclusively in non‑clinical, non‑human experimental systems. The following in‑vitro applications are well documented in peer‑reviewed literature, where the peptide serves as a tool compound to probe biological mechanisms.
Melanogenesis and Pigmentation Pathway Studies
Cultured melanocytes (e.g., B16‑F10 mouse or primary human epidermal melanocytes) treated with Melanotan II show dose‑dependent increases in tyrosinase activity and melanin content. These assays rely on the peptide’s agonist activity at melanocortin‑1 receptors (MC1R) and are used to dissect intracellular cAMP‑mediated signalling. Researchers employing CRISPR‑edited cell lines use the peptide to validate receptor function downstream of MC1R.
Receptor Binding Assays for Melanocortin Receptors
Radioligand displacement assays with [¹²⁵I]‑NDP‑α‑MSH allow determination of binding affinities (Kᵢ values) at human MC1R, MC3R, MC4R, and MC5R. Melanotan II exhibits high affinity for MC1R and MC4R, making it a valuable positive control in screening campaigns for novel melanocortin receptor ligands. Data from these binding studies are published in journals such as The Journal of Biological Chemistry 以及 Peptides.
In‑Vitro Models Exploring Cyclic Peptide Mechanisms
The lactam‑bridge architecture of Melanotan II makes it a model substrate for studying cyclic peptide conformation and stability. Circular dichroism spectroscopy and NMR-based solution structure determinations reveal that the ring constrains the bioactive turn conformation. These biophysical analyses inform the design of more stable analogues for tool‑compound libraries.
Frequently Asked Questions About Bulk Purchase
What documentation is provided with each order?
A standard bulk shipment includes a batch‑specific certificate of analysis (CoA), the mass spectrum, an HPLC purity report, and a material safety data sheet (MSDS). If endotoxin data were obtained, those results are also included. For institutions requiring GLP‑like traceability, additional documents such as a statement of origin (synthesis location) and a dated certificate of compliance can be arranged at the time of ordering.
How is the peptide packaged for bulk shipments?
The lyophilised powder is filled into pharmaceutical‑grade glass vials, back‑flushed with inert gas, and sealed with rubber stoppers and aluminium crimp caps. Several vials are placed in a resealable mylar barrier pouch containing a desiccant sachet. The pouch is then packed in an insulated expanded‑polystyrene container with pre‑conditioned gel packs or dry ice, enclosed in a sturdy corrugated outer carton. This triple‑barrier approach protects against moisture, light, and temperature excursions.
Are certificates of analysis included?
Yes. Each batch ships with a CoA that enumerates the lot number, peptide content (net weight), chromatographic purity, counter‑ion content, residual moisture (Karl Fischer titration), and endotoxin level when applicable. Additional analyses, such as tandem mass spectrometry sequencing or amino‑acid analysis, can be provided on request for large‑scale supply agreements.
What is the return policy for research‑grade materials?
Because these peptides are produced to order and intended for laboratory research, returns are generally limited to quality‑related complaints. If independent analysis demonstrates that the product does not meet the agreed‑upon specifications, the supplier will typically replace the material or issue a credit note. Buyers are encouraged to retain a dedicated aliquot of each lot for reference purposes and to store the peptide strictly as recommended to prevent degradation that might be misconstrued as a manufacturing defect.
仅限研究用途的说明： All Melanotan II products described here are intended strictly for laboratory research and scientific investigation. They are not for human or veterinary use, nor for any diagnostic, therapeutic, or prophylactic purpose. No assertions concerning safety, biological activity in living organisms, or potential health effects are implied. Institutions ordering these materials confirm their obligation to use them in compliance with all applicable laws, regulations, and institutional research policies.
仅限研究用途。不得用于人类或兽医用途。.
