A big issue is whether the protein is expressed in a soluble, soluble but aggregated, or insoluble form. If it is soluble but aggregated or insoluble, you may have a lot of trouble getting the protein correctly folded and in a soluble, unaggregated form for further work, if that is what you need.

If the protein has a tendency to be expressed in a soluble but aggregated or insoluble form, you might be able to change the expression construct to improve the situation, such as by making a fusion protein with a solubilizing protein or domain.

Also consider what method you will use for purification. Various affinity tags are available to help with purification.

Thank you Adam

Dear Julien Pompon

it depends if you have already some data about protein expression and solubility and you would like just to produce at Genescript a protein with a known protocol or as Adam B Shapiro told you, the solubility and expression is unknown, it it the first time that you test it, since Genescript as Biointron. THey are very good, cheap and fast to produce proteins with solid protocol, (e.g monoclonal antibodies) while is certainly more complex delegate to them the set-up of a new protocol for a poorly characterized protein from scratch.

good luck

Manuele