Proper reconstitution of lyophilized peptides is critical for maintaining peptide integrity, activity, and shelf life. This guide covers buffer selection, techniques, and best practices.
Buffer pH Range Compatibility Best For Sterile water (BAC-free) 5.5–7.0 Most peptides General use 0.9% NaCl 5.5–7.0 Most peptides Injection 5% Mannitol 5.5–7.0 Sensitive peptides Pulmonary 10 mM Acetate 4.0–5.5 Acid-stable peptides Long-term storage 10 mM Phosphate 6.0–8.0 Base-stable peptides Physiological pH 50 mM Glycine 3.0–4.0 Acid-stable peptides Stabilization
Allow peptide to reach room temperature
Add buffer slowly down the vial wall (not directly onto peptide)
Gently swirl or invert (do NOT shake)
Allow 5–10 minutes for complete dissolution
Visually inspect for particulates
Only for peptides that resist shear forces
Brief pulses (2–3 seconds)
Check for aggregation or foam
Not recommended for large peptides (>30 aa)
Concentration (mg/mL) = Peptide mass (mg) / Volume (mL)
Molar (mM) = Mass concentration (mg/mL) / MW (kDa)
Final volume = (Current concentration × Current volume) / Final concentration
Issue Cause Solution Insoluble precipitate Hydrophobic peptide Add 10–20% acetonitrile or DMSO Foaming Vigorous mixing Gentle inversion only Cloudiness Aggregation Lower temperature, change buffer Color change Oxidation Use fresh buffer, add antioxidants Low recovery Adsorption to vial Pre-treat vial with BSA or polysorbate 80
Condition Duration Notes 2–8°C 1–4 weeks Short-term working -20°C 1–6 months Avoid freeze-thaw cycles -80°C 6–12 months For long-term storage Lyophilized Years Store desiccated at -20°C
Add 1–5 mM DTT or TCEP to prevent oxidation
Use nitrogen-purged buffers
Store under inert atmosphere
Use phosphatase inhibitor cocktails
Avoid alkaline buffers (promote dephosphorylation)
Store at -80°C
Pre-dissolve in organic solvent (DMSO, DMF, acetonitrile)
Dilute into aqueous buffer slowly
Use sonication if needed (bath sonicator, 5 min)
