Peptide storage

Peptides generally need to be kept away from light for long-term storage, and should be stored below -20 degrees, the effect is better at -80°C, and can be stored at 4 °C in the short term. Can be transported at room temperature for a short time. peptides are stable at -20 ° C or lower, especially when freeze-dried and stored in a dryer.

Before opening the package and weighing, please balance the peptide in the dryer to room temperature. If the peptide is not balanced to room temperature, it will easily condense with water after opening the lid, which will reduce the stability of the peptide product.

Peptides containing Cys, Met or Trp are easily oxidized, and deoxidation buffers are essential for their dissolution, as this peptide is easily oxidized by air, which is reduced by nitrogen or argon protection before sealing the bottle. Peptides containing Gln or Asn degrade more easily, and all of these peptides have a shorter shelf life than simple peptides that do not contain these problematic peptides.

Peptides with an N-terminal amino acid that is Gln are very unstable and will degrade within a few days, so it is recommended to design the sequence without Gln appearing at the N-terminal.

Do custom peptides guarantee the solubility of peptides in specific solutions?

We cannot predict the solubility of polypeptides in water by studying their structure. We cannot guarantee the solubility of the product in water or other solvents.

However, the ε-amino group of lysine and the guanidine of arginine often help to predict solubility, especially for short peptides. In contrast, acidic peptides containing aspartate and glutamate tend to be insoluble in water, but soluble in dilute ammonia or alkaline buffers.

If more than 10mg of peptides are ordered, the dissolution of 1mg of peptides in 0.5~1ml DMF, water at room temperature can be tested

Can the activity of custom peptides be guaranteed?

The activity of custom peptides is affected by several factors. What can be guaranteed is that the product sequence is correct (Mass result guarantee) and the purity is up to standard (HPLC result guarantee). For activity, there is no guarantee as there is no specific test method.

There are several factors that may be helpful in ensuring activity:

A. Generally, the completed custom peptide is in the form of TFA salt, and if the customer needs to study the charge of the peptide, etc., it is necessary to require the peptide to be desalted.

B. Generally completed custom peptides are in the form of TFA salt, and some customers will require it to be converted to acetate.

The above are some notes in custom peptide synthesis, hope to help you.