Question 1

What is peptide reconstitution?

Accepted Answer

Peptide reconstitution is the process of dissolving a lyophilised (freeze-dried) peptide powder into a sterile solution, typically bacteriostatic water, to create a liquid suitable for precise measurement in laboratory research. The reconstituted solution allows researchers to draw accurate micro-doses using an insulin syringe.

Question 2

What is bacteriostatic water and why is it used for reconstitution?

Accepted Answer

Bacteriostatic water is sterile water that contains 0.9% benzyl alcohol as a preservative. The benzyl alcohol inhibits bacterial growth, which extends the usable life of the reconstituted peptide solution. It is preferred over plain sterile water because it allows the solution to be stored and used over multiple research sessions rather than requiring single-use preparation.

Question 3

How do I convert insulin units (IU) to millilitres (mL)?

Accepted Answer

On a standard U-100 insulin syringe, 100 insulin units (IU) equals 1 mL. Therefore, 1 IU equals 0.01 mL. To convert IU to mL, divide the number of units by 100. For example, 25 IU equals 0.25 mL, and 10 IU equals 0.10 mL. This calculator performs this conversion automatically.

Question 4

How should reconstituted peptides be stored?

Accepted Answer

Reconstituted peptide solutions should be stored in the refrigerator at 2-8 degrees Celsius (36-46 degrees Fahrenheit). Avoid freezing the reconstituted solution as this can damage the peptide structure. Keep the vial upright and protected from light.

Question 5

What syringe size should I use?

Accepted Answer

The choice of syringe depends on the volume you need to draw. A 0.3 mL (30 IU) syringe offers the highest precision for very small volumes. A 0.5 mL (50 IU) syringe is the most commonly used as it balances precision with capacity. A 1.0 mL (100 IU) syringe is suitable when larger volumes are required. Use the smallest syringe that can accommodate your draw volume for maximum accuracy.

Question 6

How much bacteriostatic water should I add to my peptide vial?

Accepted Answer

The amount of bacteriostatic water depends on the peptide quantity in the vial and the concentration you wish to achieve. Adding more water creates a more dilute solution, making it easier to measure small doses accurately. A common starting point is 2 mL of water for a 5 mg vial, which yields a concentration of 2,500 mcg/mL. Use this calculator to find the right volume for your specific requirements.

Question 7

What does the graduation mark on the syringe mean?

Accepted Answer

The graduation mark indicates which line on your insulin syringe to draw to. Each small line on a U-100 insulin syringe typically represents 1 IU (0.01 mL). The calculator rounds the draw volume to the nearest whole unit mark for easy reading. On a 0.5 mL syringe, the 25 mark represents 0.25 mL, which is half the syringe capacity.

Question 8

Why does the calculator show my draw volume exceeds syringe capacity?

Accepted Answer

This error appears when the required volume for your desired dose is larger than the selected syringe can hold. You can resolve this by adding more bacteriostatic water to dilute the solution (increasing the water volume), using a larger capacity syringe, or reducing the desired dose amount. The calculator will update in real-time as you adjust these values.

Peptide Reconstitution Calculator

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