Answers

1. Do you offer protein expression in expression systems other than HEK293 and CHO?
No, only in mammalian cells. They have the advantage of allowing full posttranslational modification of expressed proteins.
 
2. Which cell type do you use for expression?
HEK293 and CHO cells.

3. Do you use adherent or suspension cells?
We use HEK293 and CHO cells that are adapted to growth in suspension, but we can use adherent cells for protein expression if necessary.
 
4. How do you cultivate your cells and what is your maximum culture volume?
We use shaker cultures and wavebag technology. Currently 10 L is our maximum culture volume.
 

5. Can you produce membrane proteins?
No, currently we focus on secreted proteins (i.e., antibodies or cytokines) or secretable proteins with an artificial secretion leader.

6. What exactly are BestExpresser and Best-in-Class Services?
When you order BestExpresser service, we synthesize different versions of your gene optimized using different optimization strategies (i.e., wild type, standard optimization, and gene-specific optimization). We then subclone these versions of the genes into the same expression vector and compare their expression performance (for example, by western blot analysis). You receive all three constructs and a report with detailed information on the results (gene synthesis and subcloning not included).

When you order Best-in-Class, service, we synthesize different gene variants encoding different protein variants, subclone these genes into the same expression vector, and compare the different versions of your protein in an expression test (i.e., western blot analysis). You receive all constructs and a report with detailed information on the results (gene synthesis and subcloning not included).

7. Is the price for the generation of the expression vectors included in the cell lines and protein services?
No, the prices are only for the cell line and protein services; gene synthesis, subcloning, and plasmid preparation work is not included. If desired, we can send the expression vectors with your gene and keep a portion of the DNA for GeneArt® cell lines and protein service work.
 
8. Can I send you my own expression construct for the production of protein?
We recommend that you let us produce an expression-optimized gene subcloned into a vector of your choice for the production of your protein. But we can produce protein from your construct as long as you test it for expression first and send us the results of your analysis; e.g., a Coomassie picture with a rough protein quantification, and information on the cell culture volume you used.

9. I want a certain mass of protein; what is the price?
In order to provide a firm price estimate, we need information on the productive performance of your protein. That is the purpose or the GeneArt® Genes-to-Proteins Pilot production where we evaluate expression and purification performance of your construct. Once the pilot is complete, we can provide you with a binding quote for a specific protein amount.
 
10. What is the price range for GeneArt® services; do you have an overview on the prices for the different services?
Unfortunately, we do not. Since cell line and protein production projects are so different and individual, each project is priced separately. Please define a specific project in an email to our customer support and we will get back to you with a price quote.
 
11. Can I have an overview of your services?
Yes, we'll provide you with a service overview if you send an email to geneartprotein@lifetech.com. Please specify what service you are most interested in (Genes-to-Expression, Genes-to-Proteins, or Genes-to-Cell lines).

12. What protein purification methods do you use?
We use all available methods for purification, for example, affinity tag for purification, ProteinG/A (for antibodies or their derivatives), or combinations of ion exchange/hydrophobic interaction chromatography and gel filtration chromatography.
 
13. If you use an affinity tag, can you cleave it off the protein after purification?
Yes, we use tags that can be cleaved off after purification and removed from the purified protein (for example, by introducing a thrombin or TEV protease cleavage sequence during gene synthesis—some amino acids may be left on the protein after cleavage).
 
14. What is meant by "uncloned stable cell line" or "stable cell pool"?
After transfection, the cells are cultivated until only stably transfected cells are growing in the culture. For the "polyclonal" service, we check for transgene expression and deliver this cell pool of uncloned, stable transfected cells.

For the "clonal" service, we isolate several hundred different cells from a stable cell pool, check for transgene expression and deliver clonal cell line(s) (progeny of a single cell) expressing the protein of interest.