How to Reconstitute Peptides

Reconstitution is the step where most research protocols introduce avoidable error. A correct reconstitution preserves peptide integrity; a sloppy one can ruin a multi-hundred-dollar vial in under a minute.

1. 1

   Let the vial reach room temperature

   Take the lyophilized vial out of the fridge and let it warm for 15–20 minutes. Cold vials increase the risk of the stopper popping loose and shock-denaturing fragile peptides.

2. 2

   Wipe both stoppers

   Alcohol swab the rubber stopper on both the peptide vial and the bac water vial. This is the single biggest contamination vector in a home lab setup.

3. 3

   Draw the bac water

   Using a U-100 syringe, draw the pre-calculated volume of bacteriostatic water. Typical volumes: 2 ml for mg-range compounds, 3 ml for mcg-range compounds. Use the Dosage Calculator to confirm.

4. 4

   Inject slowly down the side of the vial

   Angle the needle against the inside wall and push the plunger slowly. Blasting water directly onto the lyophilized cake can denature fragile peptides and cause foaming.

5. 5

   Swirl — never shake

   Rotate the vial gently between your fingers until the powder fully dissolves. Shaking introduces shear forces that can damage peptide structure. Most compounds dissolve in under a minute.

6. 6

   Inspect the solution

   The solution should be clear. Cloudiness, floating particles, or a persistent film are all failure modes — do not use.

7. 7

   Label and refrigerate

   Label with the reconstitution date, concentration (mcg/ml), and compound name. Refrigerate. Most reconstituted peptides keep ~28 days at 2–8 °C.