The solubility of peptides varies depending on its amino acid sequence and modifications.

Many peptides dissolve easily in water, some, especially those containing multiple hydrophobic amino acid residues, may not readily dissolve. As a general procedure, we recommend first attempting to reconstitute peptides in sterile, distilled water, with sonication if necessary. If solutability is still a problem, addition of a small amount of dilute (approximately 10%) aqueous acetic acid (for basic peptides) or aqueous ammonia (for acidic peptides) may facilitate dissolution of the peptide. It may be desirable, initially, to determine solutability on an aliquot of the total sample. The buffer of choice for your experiments should only be added after the peptide is fully in solution, since salts may promote aggregation and therefore create solubility problems.

 

Amino Acid Characteristics

Recommended Solvent

Hydrophilic residues (KRHDEN)

H2O

Hydrophobic residues (AVLIMFW)

Low solubility in aqueous solvents; are soluble in organic solvents (DMF, DMSO, TFA, Acetonitrile)