An antigen is a substance which is used to generate the production of antibodies. In the case of this PolyExpressTM package, this is either a native protein or peptide sequence.

The origin of your target antigen is the type of organism that the protein or peptide sequence to be used as an antigen originally came from.

An accession number is a unique identification given to a biological polymer sequence and may be found in protein databases such as UniProt.

Peptides created through GenScript's OptimumAntigen™ design program have many advantages over full proteins when it comes to antibody production. Our OptimumAntigen™ Design Tool combines the industry's most advanced algorithms with GenScript's time-tested expertise. Each peptide antigen is measured against several protein databases to confirm the desired antibody and epitope specificity. We guarantee a polyclonal antibody with ELISA titer of 1:32,000 or better for any host with the aid of our antigen design tool and unique antibody production technology, or we will restart the project free of charge until the guarantee is met. Why are peptide antigens better? It is thought that anti-peptide antibodies against carefully selected peptides are more specific than those generated from longer sequences, such as native protein. With antibodies against whole protein sequences, it is impossible to know whether the epitopes are located within the folded protein while anti-peptide generation gives some control over this factor and helps to identify surface epitopes.

Our analysis shows that there is a ≥ 94% success rate in recognizing native proteins using WB with PolyExpress™ Gold (3 different regions of the antigen being used as targets for antibody generation) and ≥84% success with PolyExpress™ Silver (2 different regions being used for antibody generation). These rates apply when GenScript-deigned peptide antigens are generated. With 3 different regions of the antigen being used targets for antibody generation, there is a much greater chance that you will produce an antibody which recognizes your native protein. Ordering PolyExpress™ Gold and generating 3 antibodies at one time will save you time as you will not have to test the first antibody before determining that you should target another part of the antigen and try again, while optimizing your outcome as ordering more antibodies will not increase the already high ≥ 94% success rate much.

Lyophilized delivery means that the antibody has been freeze-dried for shipment and storage. The process of lyophilization extends the shelf life and preserves the bioactivity of antibodies. Unlabeled antibodies are stable in this form at room temperature, without loss of quality, for weeks or even months and for years at 4°.
Antibodies delivered in liquid form have been reconstituted and so the antibody is ready for use. This antibody is generally stable at -20° for one year. Delivery of antibodies in liquid form protects them from possible loss of function which may be associated with lyophilization in some cases, more often involving mAbs.