What is DNA?
Sometimes called the "blue print of life", DNA is a complex protein that carries the genetic code of an organism. All common forms of life, such as viruses, bacteria, plants, and animals carry a complete copy of their own DNA in each of their cells. Many related organisms have similar DNA, but there are small differences in the DNA sequence that are unique to each organism.
What is the DNA-PCR test?
The letters PCR stand for polymerase chain reaction. The DNA-polymerase chain reaction or DNA-PCR is a highly specialized diagnostic test that is used to identify the presence of specific DNA in a sample.
How is DNA-PCR used in veterinary medicine?
The most common use for DNA-PCR in veterinary medicine is detecting the presence of infectious organisms, such as viruses, bacteria, and some types of parasites. Less commonly, DNA testing is used to determine parentage, and also to search for genes responsible for inherited diseases.
How does DNA-PCR work to find infectious organisms?
The principle behind DNA-PCR is that each organism has a section of DNA that is unique, and like a fingerprint it identifies that organism, and only that organism. If the DNA sequence of a particular organism is known, then a diagnostic "probe" can be designed that will identify the "fingerprint" region of that organism’s DNA. In a test sample, if the probe finds the "fingerprint" DNA then the organism is present.
Is DNA-PCR a good test?
The DNA-PCR is excellent test for many reasons, but especially for its ability to find extremely small numbers of infectious organisms - sometimes a single strand of DNA is all that is needed for the test to be positive. Furthermore, it a superior test for detecting infectious organisms, especially those that are difficult to detect by other methods.
Can the DNA-PCR test be wrong?
Any diagnostic test can be wrong - no test is perfect. The DNA-PCR is a technically demanding procedure, and errors may occur. However, the error rate is extremely small; in qualified laboratories, the potential for error is minimized through the use of stringent protocols and highly trained professionals. The enormous diagnostic power that DNA-PCR offers greatly outweighs any of its weaknesses, and provides veterinarians with an invaluable tool in the battle against infectious disease.
Based on material written by Kristiina Ruotsalo, DVM, DVSc, Dip ACVP &
Margo S. Tant BSc, DVM, DVSc. and modified with permission from Lifelearn Inc.
© Copyright 2004 Lifelearn Inc.
