1. How should I store and handle my synthesized peptides?
Peptide storage guidelines:
Peptides should be stored in lyophilized form at -20°C or preferably at
-80°C in a sealed container with desiccant in order to minimize peptide
degradation. Under these conditions, the peptide can be stored for up
to several years and the following activities can be prevented such as
bacterial degradation, secondary structure formation, and oxidation.
Open the package: It is better to equilibrate the peptides to
room temperature in a desiccator prior to opening and weighing. Failure
to warm up beforehand can cause condensation to form on the product
when the bottle is opened and this will reduce the stability of the
Weigh peptides: Weigh out you needed quantity of peptide
quickly and store all unused peptide at -20°C or less. Sequences
containing cysteine, methionine, tryptophan, asparagine, glutamine, and
N-terminal glutamic acid will have a shorter shelf life than other
2. How should I dissolve peptides?
It is necessary for you to test a portion of the synthesized peptide
first before dissolving the entire peptide sample. You may need to test
different solvents until you find an appropriate one. It is necessary
to sonicate the peptide solution because sonication enhances
- If the peptide is acidic, add 0.1M ammonium bicarbonate to dissolve the peptide and add water to the desired concentration.
- If the peptide is basic, add 25% acetic acid to dissolve the peptide and add water to the desired concentration.
- If peptides are still insoluble, add acetonitrile to 20 %(v/v), and sonicate the sample.
- If, after sonication, the peptide has not dissolved completely,
lyophilize and remove the volatile buffer solution such as water,
acetic acid or acetonitrile. When the sample is completely dry,
dropwisely add DMF or DMSO until the peptide dissolves. Slowly dilute
the solution with water to approximately 10% (v/v) DMF or DMSO. Dilute
the stock solutions to the same peptide concentration.
- In order to prevent or minimize peptide degradation, store the
peptide in lyophilized form at -20°C or preferably at -80°C. If the
peptide is in solution, freeze thaw cycles should be avoided by
freezing individual aliquots.