Using cDNA as an immunogen has many potential benefits. cDNA is a prerequisite for making transfected cells. It is considerably easier, faster and less expensive to make than purifying native proteins or producing recombinant proteins. Since the animal’s own cells read the cDNA and produce the protein, it is more likely to be properly folded and have any post-translational modification observed in the native protein. Screening sera from immunized animals is often cleaner as well. The downside is that cDNA immunizations are much more difficult to do technically. It can be accomplished either using a gene gun for subcutaneous route or injected intramuscularly or intravenously. cDNA immunization is common practice during vaccine generation.