Peptides come in lyophilized (freeze-dried) form and need to be reconstituted with bacteriostatic water before use. The concentration after reconstitution depends on the amount of water used and the original amount of peptide.
Step 1: Calculating How Much Water to Use
The goal here is to reach a desired concentration that allows for easy dosage measurement.
The basic formula is:
For example, if you have a 5mg vial of peptide and you want a concentration of 1mg/mL, you'll need to add 5mL of bacteriostatic water.
Step 2: Reconstituting Peptides
Sanitize: Always start by sanitizing your hands, vial, and the top of the bacteriostatic water with alcohol swabs.
Mixing: Using an insulin syringe, draw the desired amount of bacteriostatic water. Insert the needle into the peptide vial and let the water slide down the glass. Do not shoot directly onto the lyophilized peptide to avoid degradation.
Dissolving: Gently rotate the vial between your fingers. Do not shake vigorously as it can damage the peptide structure.
Step 3: Measuring Dosages
After reconstitution, use an insulin syringe to withdraw your dose. The concentration you've created will guide the volume you need to measure.
For instance, at 1mg/mL, for a 0.5mg dose, you'd draw up to the 0.5mL mark on the syringe.
Combining Vials for Larger Quantities
To combine vials, you must calculate the total amount of peptide in all vials and the total volume of liquid you will end up with. There is a calculator for blends you can use.
For example, combining two 5mg vials each reconstituted in 5mL of water gives you 10mg in 10mL, maintaining a 1mg/mL concentration. Adjusting concentrations requires recalculating the total volume of water needed for your desired concentration with the new total amount of peptide.
Using a Peptide Calculator
A peptide calculator simplifies these calculations. You input the peptide amount (mg), desired concentration (mg/mL), and it calculates the volume of water needed. Some calculators also help with combining vials by adjusting for changes in concentration and volume, making life easier and minimizing human error.
Link: https://peptidecalc.com/
Safe Large Vials or Bulk Peptide Storage
Proper peptide storage is crucial for maintaining their integrity, especially when dealing with bulk or large vial quantities. Peptides, due to their biochemical nature, are susceptible to degradation within 30 days of reconstitution. Properly stored peptides can retain their potency over several months saving you time and money.
Tips for Precision
Always use a quality insulin syringe for precise measurements.
Consider the peptide's stability and storage requirements post-reconstitution.
Double-check your calculations or use a peptide calculator to ensure accuracy.
Handling peptides with precision ensures the effectiveness of your research or treatment. Understanding the basics of reconstitution, dosage measurement, and the convenience of a peptide calculator are crucial steps in peptide handling. With practice and attention to detail, these processes become second nature.
This guide aims to demystify the process and provide a solid foundation for anyone working with peptides, from research enthusiasts to biotechnology professionals. Remember, accuracy is key, and when in doubt, calculate twice.
References:
American Peptide Society. (n.d.). Peptide Handling and Storage Guidelines. Retrieved from American Peptide Society website.
Smith, J.A., & Jones, B.C. (2018). Basic Practices in Peptides Handling. Journal of Peptide Science, 24(5), e3082. https://doi.org/10.1002/psc.3082
Lee, V.H.L. (Ed.). (2017). Practical Guide to Peptide and Protein Drug Delivery. Springer. https://www.springer.com/gp/book/9783319583459
Peptides.org. (2020). Peptide Reconstitution and Dosage Calculation. Retrieved from Peptides.org website.
Patel, M.N., & Armstrong, G. (2016). Stability of Peptides in Solution. International Journal of Pharmaceutics, 499(1-2), 1-13. https://doi.org/10.1016/j.ijpharm.2016.01.045
García, M.E., Blanco, J.L., & Fernández, G. (2021). Biological and Chemical Stability of Peptides: A Review. European Journal of Medicinal Chemistry, 210, 112981. https://doi.org/10.1016/j.ejmech.2020.112981
Kaur, H., & Singh, S. (2019). Peptide Dosage and Storage: An Overview. In Peptide Applications in Biomedicine, Biotechnology and Bioengineering (pp. 199-216). Woodhead Publishing. https://www.elsevier.com/books/peptide-applications-in-biomedicine-biotechnology-and-bioengineering/kaur/978-0-08-100736-5
Spot on. Just what I needed. Thanks.