Selecting the proper antigen is one of the most critical steps in any custom antibody project. In most cases, scientists either use protein antigens or peptide antigens for this purpose. In some cases, an innovative new technique called DNA immunization allows the use of DNA as antigen. Among these choices, protein antigens are generally regarded as the gold standard when it comes to high-quality antigen production for antibody-generation purposes. Their unique ability to elicit antibodies that recognize the native confirmation of the target protein makes them a superior choice over other antigen alternatives. Given their structural complexity and size, proteins are inherently strong immunogens. Added to that, antibodies generated from protein antigens recognize multiple conformational epitopes within the target protein. This characteristic enhances antibody selectivity and specificity compared to anti-peptide antibodies. Selection of the ideal antigen production platform depends on a variety of factors, some of which are described ahead in this technical note.
When Choose a Protein Antigen?
- You need an antibody that works in a variety of applications.
- Your target protein has low sequence similarity to other proteins, is relatively easy to express and purify, and non-toxic.
Given GenScript Production Team's Experience and based on customer feedback we strongly recommend the use of Protein Antigen whenever possible, for the generation of high specificity antibodies.
Protein Antigen Production in E. coli
Recombinant E. coli protein expression is frequently used for the generation of protein antigens for antibody production. To generate high specificity antibodies against your target protein, there are several considerations that need to be looked at, before initiating recombinant expression.
Considerations for Protein Antigen Production in E. coli
|Post Translational Modifications||
Schematic of Protein Antigen Production in E. coli at GenScript
Tags used for Protein Antigen Production in E. coli
To facilitate affinity purification and/or solubility, most antigens produced in bacteria are fused to a tag. Few commonly used tag choices are listed in the table below.
Small tags such as the 6His tag are less immunogenic but larger tags such as MBP and GST normally need to be removed from the antigen to minimize the incidental production of antibodies to the tag, in addition to the desired antigen. In case larger epitope tags are not cleaved prior to protein use as immunogen, additional counter screening may have to be performed in order to identify antibodies that bind uniquely to the protein antigen of interest.
Protein Antigen Production in Mammalian System
Mammalian antigen production is often preferred for the production of eukaryotic proteins. The advantage of a mammalian system is its ability to confer the appropriate post translational modifications, particularly, glycosylation. Combined with its efficient protein folding system, antigens produced in mammalian systems often resemble native conformation and demonstrate better solubility. Mammalian antigen production is therefore the system of choice for many proteins that are either eukaryotic, difficult to produce or required for antibody generation projects where detection of native antigen is absolutely critical. GenScript provides high quality transient expression services that are suitable for the production of your antigens in either CHO or HEK293 cells. Visit MamPower™ Guaranteed Mammalian Protein Expression page to learn more.
Recommended Protein Antigen Production Services at GenScript
With years of experience in developing customized Antibodies against difficult targets, GenScript brings the unique perspective of antibody experts to recombinant protein antigen production. While E. coli expression is the most routinely adopted method for protein antigen production, in some instances mammalian expression may be necessary.
For mammalian protein antigen production, visit MamPower™ Guaranteed service page. For protein antigen production in E. coli, try BacPower™ Guaranteed, our high quality, fail-safe, bacterial protein expression packages. Key features of both packages are listed below.
- Gene synthesis included – no additional cost.
- Guaranteed delivery – no cost to customer if project not delivered as required.
- Competitive price starting from $2200 for E. coli and under $5000 for mammalian.
- Rapid turnaround - in as little as 4 weeks for E. coli and 9 weeks for mammalian.
Note: Our most popular E. coli protein antigen production package is listed in the table below.
|BacPower™ Guaranteed||SC1253-85T-80||6His||3mg||≥85%||4-6 weeks|
Moving directly to antibody generation? GenScript seamlessly integrates protein production with antibody production services. We provide fast and guaranteed results with our PolyExpress™ Premium and MonoExpress™ Premium packages. Your project can progress from protein sequence to validated antibodies in as little as 18 weeks, including protein synthesis. Get a quote today to accelerate your research!
#Automatic Quote will be generated only if sequences qualify for the Guaranteed service, as determined by our proprietary sequence analysis platform, failing which, our Technical Account Manager will contact you with a custom protein production quote. Please be assured that our custom services are equally high quality and competitive as our Guaranteed services
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