Custom Protein Production

We guarantee that your target gene-of-interest is correctly synthesized using DNA sequencing.

We cannot guarantee that your protein will be expressed since expression level cannot be predicted. This is why a small-scale gene expression test to determine protein expression is performed in Phase 3. However, membrane proteins are often poorly expressed and purified. Therefore, we recommend that only soluble domains are expressed.

You only need to pay for the work that is performed. That is, if the results in Phase 3 show that the expression failed and you choose not to continue to Phase 4, you do not need to pay for Phase 4.

The signal peptide causes the protein target to be secreted out of the cell and into the serum-free culture media where the protein content is minimal. This results in a purer purified protein since there are fewer proteins in the culture supernatant (compared to the cell lysate) to nonspecifically bind to the affinity purification column. For example, protein purity > 95% is routinely achieved with secreted proteins, whereas protein purity > 50% is often obtained with non-secreted proteins.

Sometimes the protein target will not be secreted even with the signal peptide. It is likely that, in the protein tertiary structure, the signal peptide is occluded.

The signal peptide is 25 amino acids long. It is often cleaved by proteases in cell culture, but we cannot guarantee that the signal peptide will be cleaved. Upon request, we can exclude the signal peptide in the expressed protein.

Yes. If you have already expressed your target protein successfully using your expression vector, please provide the expression conditions that you would like us to use. We can then go to Phase 4 directly. If you have not confirmed that the gene is expressed in your expression vector, we will perform a small-scale expression test in Phase 3.

It depends. Please provide us with the gene sequence and, at a minimum, 100 nucleotides flanking the gene at the 5' and 3' ends. This information is necessary because we will use restriction enzymes to cut the gene out of your plasmid and ligate it into ours (i.e., cloning). If we can clone your gene into our vector, then Phase 1 is not necessary. If the gene and flanking sequences are incompatible with any restriction digest approach, then we cannot use your gene and will have to start at Phase 1.

Also, it is important to consider whether your gene is codon optimized for the expression system.

Yes. Please indicate this in the quote request form.

We can add a cleavage site between the tag and target protein.

For example, we can add a tobacco etch virus (TEV) site between the His tag and protein-of-interest. After the His-tagged protein is purified, a His-tagged protease could be added, cleaving the His tag from the target protein. The tagless protein could then be purified from the His tag and His-tagged TEV protease using IMAC.

If the protein was expressed and purified previously, you do not need to pay for Phases 1 - 4 again. You would simply complete the quote request form for the desired amount of purified protein (Phase 5). Please make sure to include the previous sales order or invoice number in the Project Description section.