Choose the best peptide synthesis partner
The most competitive price for peptide synthesis on the market.
We guarantee to provide you with the most competitive price.
Save time and buy your peptides thanks to our online form. Delivery in 10 business days.
ProteoGenix can synthesize peptides up to 150 AA.
ProteoGenix offers an unlimited range of peptide modifications.
Your project is our priority so we will start from the beginning until we get the right peptide or you won’t pay a thing.
Our peptide synthesis service includes the lyophilized peptide and a QC report. The QC report includes:
Peptide synthesis purity grade can have an important impact on the price. However, it can also be critical for the success of your experiments. Therefore, we provide a table summarizing the peptide purity grade requested for several applications:
Crude
Interaction studies (ligand-receptor, protein-protein…)
Mutation screening
Sequence optimization
>70%
Polyclonal antibody production
ELISA assays
>80%
Monoclonal antibody production
In vitro tests
In vivo studies
Quantitative inhibition studies
Quantitative interaction studies
NMR studies
>95%
Clinical trials
Crystallography
Quantitative studies
If your application is not mentioned in the table, please contact our account manager. He will be glad to help you choose the most relevant peptide purity grade!
ProteoGenix can deliver a solubility test service. In this case, you don’t need to consume part of your peptide stock for solubility testing.
If you choose to make it by yourself, the most commonly used method is based on charge determination. For small peptides with up to 5 amino-acids, distilled water remains the first option. For other cases, you can refer to this guide:
Attribute -1 to each acidic residue (Asp / D, Glu / E) and to the terminal carboxylic acid. Then, assign +1 to each basic residues (Arg / R, Lys / K, His/h) and the terminal amine. Sum up both values to determine the overall charge of your peptide.
If the overall charge value is positive, try to dissolve your peptide in water. In case the peptide does not dissolve, acidify your solution with an acetic acid solution (10 to 30%). Add TFA if acetic acid does not allow peptide dilution du sufficient concentration.
In case the overall charge is negative and the peptide does not contain cysteine residues, try to dissolve your peptide in water. If the peptide does not dissolve, add ammonium hydroxide to obtain the desired concentration.
If the overall calculated charge is zero, the peptide can be diluted with organic solvents (methanol, ethanol, isopropanol or acetonitrile). A small amount of DMSO diluted with water can be used depending on final application. Specific care is requested for peptide containing cysteine, methionine or tryptophan residues as they are sensitive to oxidation. In these cases, replace DMSO by DMF.
Synthetic peptide represent powerful tools for polyclonal or monoclonal antibody generation. Most of the time, antigenic peptides are selected based on native protein sequence examination. Antigenic sequences are often chosen based on physico-chemical properties:
The length of the peptide antigen is also a critical point. Firstly, a short peptide (<10 AA) does not present a sufficient size to function as an epitope. Secondly, long peptides (>20 AA) can adopt conformations not reflected in the native protein structure. Thus, a 10-20 AA peptide antigen is an optimal for antibody production.
A peptide alone generally tends to elicit only a weak immune response. Consequently, it is usually conjugated to a carrier molecule. Peptide conjugation to a carrier necessitates considering two points:
Most peptide synthesis are based on Fmoc solid-phase synthesis developed by Atherton and Sheppard in the 1970s. Solid-phase peptide synthesis is based on stepwise amino-acid coupling leading to the desired peptide chain. With this method, the peptide chain is covalently attached to an insoluble resin, which consists of a synthetic polymer containing functional groups.
These groups react with the carboxylic end of N-protected amino-acids leading to a covalent coupling. Undesired reactions (and thus byproducts) are prevented by transient protection of the terminal amino group and permanent protection of amino-acid side chains. Deprotection of the solid surface coupled amino-acid, and activation of the carboxylic acid terminus of the added amino-acid, leads to amino-acid coupling. Each step is separated by a washing step allowing the removal of eventual byproducts and reagents.
Peptide synthesis consists of repeating this reaction scheme until the desired sequence is obtained. The final peptide is cleaved from the resin surface thanks to a strong acid (generally TFA).