After reconstitution, you need to know the concentration of your peptide solution to determine the correct volume per dose. The formula is: concentration = total peptide (mg) divided by total solvent volume (mL).
Example: You have a 5mg vial and add 2mL of bacteriostatic water. The concentration is 5mg / 2mL = 2.5mg/mL, or 2500mcg/mL. If your research protocol calls for 250mcg, you would draw 0.1mL (or 10 units on a standard insulin syringe).
Insulin syringes are graduated in units (U). A standard 1mL insulin syringe has 100 units. So 0.1mL = 10 units, 0.25mL = 25 units, 0.5mL = 50 units. This makes it straightforward to measure precise volumes.
When working with very small doses (under 100mcg), consider using a larger reconstitution volume to make measurement easier. Adding 5mL to a 5mg vial gives 1mg/mL = 1000mcg/mL. A 100mcg dose would then be 0.1mL (10 units), which is easy to measure accurately.
Always label your reconstituted vials with the peptide name, concentration, reconstitution date, and solvent used. This prevents dosing errors when working with multiple compounds in the same research protocol.
Disclaimer: This article is for educational purposes only. All peptides are sold for laboratory research use only. Not for human consumption.