Last reviewed
Introduction
Implementing quality control practices in research laboratories ensures reproducible results and protects your peptide investment. This guide covers practical QC approaches for research settings.
Receiving and Inspection
Initial Receipt
Documentation Check:
- Verify order matches delivery
- Confirm lot numbers
- Review Certificate of Analysis
- Check storage conditions during shipping
Physical Inspection:
- Packaging integrity
- Temperature indicators (if used)
- Vial condition
- Label legibility
Acceptance Criteria
Establish receiving criteria:
- CoA specifications met
- No shipping damage
- Appropriate documentation
- Within expiry date
Storage Management
Temperature Zones
-80°C (Long-term):
- Critical or expensive peptides
- Reference standards
- Backup samples
-20°C (Standard):
- Most lyophilized peptides
- Working stocks (powder)
- Daily use materials
2-8°C (Short-term):
- Solutions in active use
- Reconstituted peptides (limited time)
Room Temperature:
- Only if specifically stable
- Short-term only
Organization System
Implement:
- Clear labeling protocol
- Inventory tracking
- First-in-first-out rotation
- Location mapping
Label Information:
- Peptide name/sequence
- Lot number
- Received date
- Concentration (if solution)
- Expiry date
Handling Protocols
Reconstitution SOP
Standard Procedure:
- Allow vial to warm to RT (prevents condensation)
- Calculate appropriate volume for desired concentration
- Add solvent slowly down vial wall
- Gently swirl or rotate (avoid vigorous mixing)
- Verify complete dissolution (visual)
- Transfer to appropriate storage container
- Document concentration, date, analyst
Solvent Selection:
- Sterile water: First choice for most peptides
- DMSO: For hydrophobic peptides
- Dilute acid: For basic peptides
- Buffer: For specific pH requirements
Aliquoting Strategy
Why Aliquot:
- Avoid repeated freeze-thaw
- Reduce contamination risk
- Preserve sample integrity
Best Practices:
- Calculate appropriate aliquot sizes
- Use low-binding tubes
- Label completely
- Freeze rapidly
Quality Control Testing
Incoming QC
Verify supplier data (if resources permit):
- HPLC purity check
- MS identity confirmation
- Appearance verification
When to test:
- New suppliers
- Critical experiments
- Unexpected results
In-Use QC
Periodic Verification:
- Visual inspection before each use
- Activity verification for bioassays
- Concentration check if diluted
Stability Monitoring:
- Test working stocks periodically
- Compare to fresh reconstitution
- Track trending data
Documentation
Laboratory Notebook
Record for each use:
- Date and time
- Lot number used
- Amount/volume
- Experiment reference
- Any observations
Electronic Records
Maintain databases for:
- Inventory tracking
- Lot history
- Stability data
- Supplier performance
Standard Operating Procedures
Document procedures for:
- Peptide receipt and storage
- Reconstitution protocols
- Aliquoting procedures
- Disposal methods
