Moving past serology: Diagnostic options without serum

- Traditional serology has moved beyond blood as a test medium.
- A number of different samples and tissues are now frequently used in veterinary diagnosis.
- Testing can be robust and accurate and opens up the field to a variety of new opportunities.
- Molecular testing allows direct testing for the agent on a variety of tissues and samples, and pools.
- Pooling of samples can allow for more efficient and cost-effective testing.

Detecting antibodies formed in serum in response to infection is the traditional function of serology. Diagnostic modalities have included complement fixation tests, agar gel immune-diffusion, radioimmunoassay, ELISA and immunofluorescence. More recent technology now allows for the direct detection of pathogens by PCR. This review details the options for diagnostic testing using specimen types other than serum, identifying the advantages and disadvantages of these options and providing evidence for more widespread use of these techniques and specimen types.