Reconstituting a research peptide: the eight steps

Most research peptides in our range arrive as a freeze-dried powder. A few of the blends arrive as a ready-to-use liquid and need none of this. For the powders, before the compound can be used in a laboratory setting it has to be brought back into solution with a diluent, usually bacteriostatic water, at a concentration you choose. This guide covers what to have on the bench, how to work out the volume and the eight steps that keep the compound intact and the vial sterile from the first draw to the last.

What to have on the bench

• Bacteriostatic water, the 0.9% benzyl alcohol solution that is the standard diluent for a multi-draw vial
• Sterile syringes, a 1 ml U-100 for draws and a larger one for adding the diluent
• Alcohol swabs, for both stoppers, every time
• The peptide vial, lyophilised powder straight from the fridge
• Refrigeration at 2 to 8 °C before and after
• A clean bench, wiped down, with nothing else on it

Work out the volume first

Concentration is the vial strength divided by the diluent volume. Our reconstitution reference calculator gives you the draw volume in units on a U-100 syringe for any reference amount, shows the concentration in mg per ml, and tells you how many draws a vial yields at that setting. Work it out before you open anything.

The eight steps

1. Set up a clean bench

Wash your hands, wipe the surface and take the peptide vial and the diluent out of the fridge. Let both stand for fifteen to twenty minutes so they reach room temperature. Cold glass sweats when it is opened, and condensation inside a vial is water you did not measure.

2. Confirm the volume

Use the calculator. The whole diluent volume goes into the whole vial, in one go. Part-reconstitution makes the concentration unknowable.

3. Swab both stoppers

Alcohol swab on the peptide vial and on the diluent vial. Let them dry before the needle goes in. Repeat this before every draw for the life of the vial.

4. Draw the diluent

With a sterile syringe, draw the planned volume of bacteriostatic water. Check the volume against the syringe graduations before you move on.

5. Add it down the inside wall

Pierce the peptide vial stopper and angle the needle so the diluent runs down the glass, not onto the powder. Push slowly. Spraying diluent straight onto lyophilised powder can cause it to clump, and clumped powder is slow to dissolve and hard to judge.

6. Let it dissolve

Swirl gently in a circle. Most compounds go into solution in one to three minutes, some take up to five. Never shake the vial. Agitation can damage the peptide structure and it does not speed anything up.

7. Look at it

You are looking for a solution that is clear and even. The colour follows the powder: a white powder gives a colourless solution, a coloured powder gives a solution of the same colour.

8. Refrigerate

Straight into the fridge at 2 to 8 °C, kept upright and out of light. As a rule, a reconstituted vial keeps for 30 to 45 days refrigerated, and unopened lyophilised powder for up to two years refrigerated or frozen. Once a vial has been reconstituted it must never be frozen. Room temperature is not for storage.

Compound-specific handling sheets are in your research library after you order.

Frequently asked

How long does a reconstituted vial keep?

Refrigerated at 2 to 8 °C, most research peptides remain stable for 30 to 45 days. Check the handling sheet for your specific compound in the research library, some differ.

Bacteriostatic water or sterile water?

Bacteriostatic water contains 0.9% benzyl alcohol, a preservative that holds back bacterial growth each time the stopper is pierced, so it suits a vial that will be drawn from over days or weeks. Sterile water has no preservative. It is clean at the point of opening and stays that way only for a single draw. The choice follows how many times the vial will be entered.

The powder has not dissolved. What now?

Keep swirling gently. Most compounds go into solution within one to three minutes, some take up to five, and denser powders can take a little longer.

What colour should the solution be?

The solution takes its colour from the powder. A white powder gives a clear, colourless solution. A coloured powder gives a solution of the same colour, so a blue copper peptide reconstitutes blue. What you are looking for is a solution that is clear and even.

Where can I buy research peptides in South Africa?

Blaque Sigma supplies lyophilised research peptides to qualified researchers across South Africa, with courier delivery nationwide and collection from Northview Shopping Centre, Northriding, Randburg.

Supplied for research and laboratory use only by qualified researchers. Not for human or veterinary consumption. Not intended to diagnose, treat or cure anything. The information here is for reference only and is not medical or scientific advice.