Native proteins make excellent antigens and have traditionally been used to raise antibodies for different purposes. However, some proteins are not easy to isolate in sufficient amounts for characterization. Only a small fraction of these potentially useful proteins have been isolated and characterized. This renders most native proteins impractical as a means of generating antibodies. The most logical alternative is to generate antibodies against peptides derived from native protein sequences. In some instances, antibodies against such peptides are even more effective than antibodies against native proteins.

1. Peptide antigen production requires only the amino acid sequence.

This is especially useful under certain conditions:

• The protein has not been discovered, but the gene sequence has.
• The protein has been discovered but has not been fully sequenced.
• The protein is not available in sufficient quantities.
• The protein cannot be successfully expressed using recombinant techniques.

2. Peptide antibodies demonstrate enhanced specificity.

This offers the following benefits:

• Eliminates or minimizes potential cross-reactivity between structurally homologous proteins.
• Enables the production of antibody to the targeted epitope.
• Enables the production of antibodies for proteins with post-translational modifications.

3. Peptide affinity purification are convenient and cost-effective.

This offers the following benefits:

• Enables high efficient, relatively inexpensive immunoaffinity purification.
• Enables production of high purity and monospecific antibody to the targeted epitope by cross-adsorption with similar peptides.