Diagnosis of parasitic disease.

Diagnosis of parasitic diseases requires highly sensitive and specific tests. In many cases the identification of parasites concerns their epidemiology and it is important to distinguish between species and subspecies. Conventional techniques including serology and microscopy do not always meet these requirements. The principle of nucleic acid probes is that a specific sequence of the parasite's DNA is isolated and used in a hybridisation assay to identify homologous parasite DNA from infected material. Since DNA normally remains the same during every stage of the parasite's life cycle this technique has many applications. The use of DNA diagnostics in the identification and differentiation of certain animal parasites is discussed.