Why Aliquot?
Aliquoting — dividing a reconstituted peptide solution into smaller, single-use volumes — is the single most effective step you can take to preserve peptide quality. Each time you open a vial, you expose the contents to temperature changes, potential contamination, and air. Each freeze-thaw cycle damages peptide structure. Aliquoting minimizes both exposures.
Planning Your Aliquots
Before reconstituting, plan how many aliquots you need and what volume each should contain. Consider your experimental protocol: how much peptide do you use per session? Make each aliquot slightly larger than one session's requirement to account for syringe dead volume.
Example: You have a 5mg vial of BPC-157. Your protocol uses 250mcg per session. Reconstituting in 2.5mL BAC water gives 2mg/mL (2000mcg/mL). Each session needs 0.125mL. Making 16 aliquots of 0.15mL each gives you 16 sessions with a small buffer per aliquot.
Materials Needed
Sterile microcentrifuge tubes (0.5mL or 1.5mL depending on aliquot size), sterile syringes and needles, alcohol swabs, a permanent marker or printed labels, and a clean workspace wiped with 70% isopropyl alcohol.
Procedure
Step 1: Reconstitute the full vial as normal using bacteriostatic water.
Step 2: Using a sterile syringe, draw the planned aliquot volume from the vial.
Step 3: Dispense into a sterile microcentrifuge tube. Use a fresh needle for each tube if maximum sterility is needed.
Step 4: Label each tube with peptide name, concentration, date, and lot number.
Step 5: Place aliquots for near-term use (within 4 weeks) in the refrigerator at 2-8C. Place remaining aliquots in the freezer at -20C.
Storage Guidelines
Refrigerated aliquots: use within 3-4 weeks. Frozen aliquots: stable for 3-6 months depending on the peptide. When ready to use a frozen aliquot, thaw at room temperature or in a 2-8C refrigerator — do not heat. Use the entire aliquot in one session. Do not refreeze.
Common Mistakes
Using non-sterile tubes contaminates the peptide. Making aliquots too large wastes material when partially used tubes must be discarded. Not labeling properly leads to confusion about concentration, age, and identity. Refreezing thawed aliquots causes cumulative freeze-thaw damage — each cycle degrades quality.
