ZOOLOGIX avian & livestock diagnostic testing
Why use PCR to detect diseases of birds and
Molecular diagnostic testing using PCR (Polymerase Chain
Reaction) has revolutionized the way veterinarians,
researchers, field biologists, zoos, breeders and other animal
care facilities maintain bird and animal health and obtain
The sensitivity, specificity and speed
with which pathogens and mutations are identified by PCR enable diagnostic,
research and monitoring possibilities unavailable using other
techniques. Molecular techniques represent a dramatically
effective tool for the diagnosis of disease in populations of
birds and livestock.
testing, nucleic acid -- DNA or RNA -- is isolated from a
specimen, then amplified (after an extra reverse transcription
step in the case of RNA) using highly specific primers
complementary to known target sequences. Positive and
controls are run simultaneously; internal controls monitor
extraction and PCR efficiency. Each sample is run in duplicate
aliquots to check repeatability. Amplification is visualized and recorded using state-of-the-art protocols and
samples be collected?
pathogens shed intermittently. Therefore, for antemortem testing
it is usually best to collect samples
when a bird or animal is symptomatic. Often pathogen titers
spike early in a bout of symptoms, so ideally samples should be
collected early in a bout of symptoms, and when symptoms are
worst. It is possible for treatments to reduce symptoms and
shedding temporarily but not entirely clear the infection. If
treatment was administered, typically you should wait at least a
week following treatment, and/or until symptoms return, before
collecting a sample for testing.
How is molecular, PCR-based
testing complementary to other kinds of testing?
Cross-reactivity reduces the specificity of many
serological tests: a positive result can be caused by
organisms other than the target. Molecular assays, on the
other hand, are highly specific because they detect genetic
sequence unique to the target pathogen. Even closely related
pathogen strains can often be distinguished.
The influence of some sources of false positives is
reduced in molecular testing, because while other testing
methods detect antibodies to pathogens which may not still
be present, molecular assays detect the genetic material of
the pathogen itself -- a direct indication of presence of
the pathogen in the sample.
Infections can often be identified
very early in a bout of symptoms. Detection is not
dependent on elevated antibody levels, which may take days
or weeks to occur.
Hosts with high titres of some viruses can actually
exhibit very low antibody levels as their immune systems are
challenged by an infection. This can result in false
negative diagnoses if antibody testing alone is used.
PCR's exquisite sensitivity allows detection of a target
pathogen in a sample even if present in very low titres, and
even from very small sample volumes.
Many different sample types are appropriate for PCR
testing - not just serum. Check our
assay datasheets for any test's sample requirements.
Since 2004, Zoologix has served animal care professionals with molecular diagnostic testing for
infectious diseases that affect birds, livestock and other
animals. Other testing facilities perform PCR testing as a
sideline. Because we specialize in PCR assays for infectious
diseases of animals, our lab staff are adept at performing
protocols designed to maintain specimen integrity and maximize
assay specificity and sensitivity. We provide fast turnaround
and competitive pricing in each of our assay categories.
As an independent,
dedicated diagnostic laboratory not affiliated with any clinic
or corporate conglomerate, Zoologix is free of incentives to
bias results. Zoologix is owned and managed by board-certified scientists
and seasoned laboratory managers with extensive experience in
molecular biology, biochemistry, zoology, assay design, quality
assurance and lab operations. Our objective is to provide to the
veterinary and research communities the fastest, highest quality
molecular infectious disease testing available.
Client samples are stored at our lab
for six months to facilitate any followup testing.
Zoologix is headquartered in Chatsworth, in southern California.
We are located near two major airports (LA International and
Burbank), UCLA, USC, CalTech and other regional research