In the process of peptide synthesis, some salt needs to be added. However, there are many types of salt, and the peptides made from different types of salt are not the same, and the effects are not the same, so today we mainly come to the synthesis of peptides, how to choose the right type of peptide salt.

1.Trifluoroacetate (TFA) 

This is a salt often used in peptide products, but due to the biological toxicity of trifluoroacetic acid is relatively large, so some experiments need to avoid the use of such salts.Our company can also provide customized synthetic peptide desalination services.

2.Acetate (AC) 

The biological toxicity of acetic acid is much smaller than that of trifluoroacetic acid, so most of the salt used in pharmaceutical peptides and cosmetic peptides is acetate, but the acetate of some products is unstable, so it is also necessary to consider the stability of the sequence.

3.Hydrochloride (HCL) 

This type of salt is rarely selected, and only some sequences use hydrochloride for special purposes.

4.Ammonium salt (NH4+) 

This kind of salt will seriously affect the solubility and stability of the product, and must be selected according to the sequence.

5.Sodium salt (NA+) 

It generally affects the stability and solubility of the product.

6.Sodium salt (NA+) 

It generally affects the stability and solubility of the product.

7. Citric Acid

The physiological toxicity of this kind of salt is relatively small, but the preparation process is very complex, so the production process needs to be developed separately according to the sequence.

8. Salicylic acid (Salicylic acid) 

Salicylic acid will affect the stability of peptide products, so it is rarely used.

The above is the type of several peptide salts, and we should choose according to the characteristics of different salts in the actual use process.

TFA is a strong acid. It can protonate any amino group. The same goes for hydrochloric acid. In the process of purification of peptides by reverse-phase HPLC, one technique is anion exchange. Load the peptide onto the column, keeping it on top, while washing with sufficient acetic acid buffer, then gradient elution with acetic acid aqueous solution/acetonitrile. After freeze-drying, the counterion TFA is exchanged. The technique relies on the hydrophobicity of the peptides. A high hydrophilic peptide will require a suitable anion exchange resin.

The use of a special reversed-phase C-18 material provides a good separation method to remove TFA. The separation of TFA, acetic acid and fluoride requires the use of stationary phases functionalized by alkyl quaternary ammonium groups. The eluent from the analytical column flows through the suppressor, reducing the total background conductance of the eluent and enhancing the conductance of analyte ions. By suppressing the conductance, the signal-to-noise ratio is improved by about 50 times compared with the uninhibited conductance.

The peptides synthesized by Omizzur Biotech are generally in the form of TFA salts. If residual TFA will affect your experiment, researchers usually recommend conversion to other salts, such as acetic acid and hydrochloride forms. These salt forms of peptides typically cost 20 to 30 percent more than TFA salts, due to the loss of peptides in the salt transfer process and the need for more raw materials.