Monoclonal antibody and nucleic acid probes for the diagnosis of avian diseases

Various properties of monoclonal antibody (MAB) and nucleic acid (NA) probes confer advantages over polyclonal antibodies in sera and permit the probes to be used to directly and rapidly detect small quantities of pathogens in body fluids, biopsy, or postmortem material. This makes it unnecessary to amplify the amount of pathogen by growth in vitro or to perform neutralization tests, procedures that are time-consuming. Even if pathogens are grown in vitro, highly specific MABs can be used in immunofluorescence tests to differentiate isolates to extents not possible using antisera. There has been much greater investment in the development of probes for the diagnosis of human disease than for veterinary disease, because of the greater commercial potential of the former. A number of factors work against the development and distribution of new probes, but most of these are only temporary impediments if demand is there. Even in human medicine, the application of new probes is in its infancy, and it is probable that it will be several years yet before probes achieve widespread use in avian diagnosis. However, the potential of some MAB and NA probes is too great to ignore.