ABSTRACT
Serology is a critical tool that allows animals or humans to be screened for exposure to an almost infinite array of foreign proteins. Serology is based on the principle that most foreign molecules are capable of eliciting a distinct humoral immune response in vertebrates. In serology, antigen–antibody complexes can be measured, and the findings can be used to aid in diagnosing the basis for illness and disease in animals. The serum neutralization test (SNT) is generally considered the gold standard when comparing different serologic tests used in determining the exposure of an animal to a virus. It is based on the property of a specific antibody subtype neutralizing a virus. The indirect format is most commonly used to determine the presence of a specific antibody. In the indirect enzyme-linked immunosorbent assay (ELISA), the primary antibody that binds to the antigen becomes the target of the secondary antibody conjugated to the enzyme.
