Selank Reconstitution Chart (Every Vial Size)

Reconstitution Principles for Selank Research

Selank is a synthetic heptapeptide derivative of the human immunomodulatory peptide tuftsin, modified with a Pro-Gly-Pro C-terminal sequence to enhance proteolytic stability. In laboratory settings, Selank is typically supplied as a lyophilized (freeze-dried) cake or powder within sealed glass vials. To prepare the compound for in vitro binding assays or preclinical rodent models, researchers must reconstitute the dry mass using a sterile, liquid diluent.

Precision in reconstitution determines the exact molarity and mass-per-volume concentration of the solution. Small variances in liquid diluent volume significantly alter final concentration, which directly affects experimental reproducibility across trial cohorts. To ensure high experimental consistency, investigators should always reference verified lot metrics via the product's certificate of analysis and utilize high-purity compounds sourced from our catalog of all peptides.

Because lyophilized peptides are sensitive to temperature fluctuations and mechanical shear stress, reconstitution requires strict adherence to aseptic techniques, gentle hydration protocols, and temperature-controlled storage environments.

Selank Reconstitution Master Reference Chart

The table below outlines common vial sizes (5 mg, 10 mg, and 20 mg) and standard diluent volumes (1.0 mL to 5.0 mL). It provides the resulting concentration in milligrams per milliliter (mg/mL) and the exact peptide mass contained within a standard 0.1 mL (100 µL) laboratory liquid sample.

| Vial Size | Diluent Volume | Resulting Concentration | Mass per 0.1 mL (100 µL) | | :--- | :--- | :--- | :--- | | 5 mg | 1.0 mL | 5.0 mg/mL | 0.50 mg (500 µg) | | 5 mg | 2.0 mL | 2.5 mg/mL | 0.25 mg (250 µg) | | 5 mg | 2.5 mL | 2.0 mg/mL | 0.20 mg (200 µg) | | 5 mg | 5.0 mL | 1.0 mg/mL | 0.10 mg (100 µg) | | 10 mg | 1.0 mL | 10.0 mg/mL | 1.00 mg (1000 µg) | | 10 mg | 2.0 mL | 5.0 mg/mL | 0.50 mg (500 µg) | | 10 mg | 2.5 mL | 4.0 mg/mL | 0.40 mg (400 µg) | | 10 mg | 5.0 mL | 2.0 mg/mL | 0.20 mg (200 µg) | | 20 mg | 1.0 mL | 20.0 mg/mL | 2.00 mg (2000 µg) | | 20 mg | 2.0 mL | 10.0 mg/mL | 1.00 mg (1000 µg) | | 20 mg | 4.0 mL | 5.0 mg/mL | 0.50 mg (500 µg) | | 20 mg | 5.0 mL | 4.0 mg/mL | 0.40 mg (400 µg) |

For custom vial masses or non-standard liquid volumes, research personnel can enter variable metrics directly into our interactive reconstitution calculator to quickly establish precise volumetric parameters.

Mathematical Formulas for Peptide Concentration

Calculating the final concentration of a reconstituted peptide requires two basic mathematical relationships. The primary formula determines the solution concentration based on mass and liquid volume:

Concentration (C) = Total Peptide Mass (M) / Diluent Volume (V)

Where Concentration (C) is expressed in mg/mL, Total Mass (M) is expressed in milligrams (mg), and Volume (V) is expressed in milliliters (mL). To determine the mass present in a specific sample volume (v), researchers use the following secondary equation:

Sample Mass (m) = Solution Concentration (C) × Sample Volume (v)

When performing micro-volume sampling with micropipettes, volume is frequently measured in microliters (µL). To convert microliters to milliliters, divide the volume by 1,000 (e.g., 100 µL = 0.1 mL). Maintaining consistency in volumetric units prevents calculation errors during sample preparation.

Step-by-Step Worked Calculation Examples

Example 1: A research laboratory receives a vial of Selank 10mg and intends to reconstitute it using 2.0 mL of Bacteriostatic Water.

Step 1: Determine total peptide mass (M = 10 mg). Step 2: Measure added diluent volume (V = 2.0 mL). Step 3: Calculate total concentration: C = 10 mg / 2.0 mL = 5.0 mg/mL. Step 4: Calculate mass per 100 µL aliquot: m = 5.0 mg/mL × 0.1 mL = 0.5 mg (or 500 µg).

Example 2: An investigator needs a final concentration of 2.0 mg/mL using a 5 mg Selank vial.

Step 1: Target Concentration (C) = 2.0 mg/mL. Step 2: Total Mass (M) = 5 mg. Step 3: Solve for Diluent Volume: V = M / C = 5 mg / 2.0 mg/mL = 2.5 mL. Step 4: Reconstitute the 5 mg vial with exactly 2.5 mL of sterile diluent to achieve the target 2.0 mg/mL concentration.

Diluent Selection and Buffer Compatibility

Choosing the appropriate solvent is critical for peptide stability and experimental integrity. The two most common diluents utilized in laboratory research are Bacteriostatic Water (Sterile Water containing 0.9% Benzyl Alcohol) and Sterile Normal Saline (0.9% Sodium Chloride).

Bacteriostatic Water is preferred when a reconstituted vial will be sampled multiple times over an extended research period. The 0.9% benzyl alcohol acts as a preservative, suppressing bacterial proliferation within the vial. Sterile Water for Injection (without preservatives) or phosphate-buffered saline (PBS) may be selected for immediate single-use in vitro cell culture assays where benzyl alcohol could potentially introduce cellular toxicity.

Preclinical studies suggest that Selank demonstrates excellent solubility in aqueous solvents across a neutral pH range (6.0 to 7.4). Avoid highly acidic or alkaline buffers unless specifically required by an analytical protocol, as extreme pH shifts can promote peptide cleavage or degradation.

Laboratory Reconstitution and Handling Protocol

To maximize compound recovery and maintain structural integrity during reconstitution, follow these standard laboratory procedures:

1. Sanitization: Allow the lyophilized vial and diluent to reach room temperature (20°C to 25°C). Clean the rubber stoppers of both vials using a 70% isopropyl alcohol wipe. 2. Pressure Equalization: Draw the intended volume of diluent into a sterile syringe. Equalize vial pressure by allowing air displacement as necessary. 3. Diluent Addition: Insert the needle through the stopper at a 45-degree angle, directing the liquid stream down the inner glass wall of the vial rather than shooting it directly onto the lyophilized cake. 4. Dissolution: Allow the diluent to naturally saturate the powder. Gently swirl the vial in a circular motion until completely dissolved. Never shake or vortex the vial vigorously, as mechanical shear stress can disrupt delicate peptide bonds and cause foam formation. 5. Inspection: Visually inspect the solution under clear light. Reconstituted Selank should yield a completely transparent, colorless liquid free of undissolved particulate matter.

Comparative Analysis with Related Synthetic Peptides

Selank is frequently evaluated alongside other regulatory and synthetic heptapeptides within neurobiological research frameworks. The most direct structural analog is Semax, a synthetic fragment of adrenocorticotropic hormone (ACTH 4-10) with an added C-terminal Pro-Gly-Pro sequence.

When planning comparative assays, researchers often examine Semax reconstitution procedures alongside Selank protocols. Both compounds exhibit similar aqueous solubility profiles due to their shared C-terminal tripeptide structural motif. Advanced modifications, such as N-Acetyl Selank Amidate, alter molecular weight and lipophilicity, which may slightly shift solubility limits and dissolution kinetics in aqueous media.

Understanding these structural nuances allows research teams operating through wholesale lab accounts to design standardized stock solutions across multi-compound comparative assay panels.

Analytical Quality Control and Quality Assurance

The accuracy of any reconstitution calculation relies entirely on the precise mass and purity of the starting material. Lower-purity peptide preparations may contain TFA (trifluoroacetic acid) salts, residual solvents, or synthesis truncated sequences that artificially skew actual active peptide mass.

PX1 Research ensures strict analytical verification across all catalog items. Every batch is manufactured in GMP-compliant facilities within the USA and subjected to rigorous testing at an independent ISO 17025 accredited laboratory. Purity is established via High-Performance Liquid Chromatography (HPLC), confirming levels equal to or exceeding 98.0%. Exact molecular mass is verified using Mass Spectrometry (MS).

Additionally, all batches undergo bacterial endotoxin testing via Chromogenic LAL assays to ensure levels remain strictly below <0.5 EU/mg. Orders ship directly from primary facilities in California and Arizona with same-day dispatch for orders placed Monday through Friday before cut-off times.

Storage, Stability, and Aliquot Protocols

Proper storage conditions are vital to maintain peptide stability before and after reconstitution. Lyophilized Selank powder should be stored at -20°C for long-term preservation, protected from direct light exposure and humidity.

Once reconstituted with Bacteriostatic Water, the liquid solution remains stable for up to 28 days when stored under refrigeration at 2°C to 8°C. If the research protocol requires single-use applications over several months, the solution should be aliquoted into micro-centrifuge tubes immediately following reconstitution and frozen at -20°C or -80°C. Repeated freeze-thaw cycles must be avoided, as phase changes degrade peptide structural integrity.

For comprehensive literature regarding peptide stability and analytical methods, explore our centralized peptide research hub.