University of Virginia Health System
Medical Laboratories
“Quality You Expect, Service You Deserve”
LABORATORY MEDICINE UPDATE
March 20, 2012
New Urinalysis Instrument in the Core Laboratory
Recently, the Core Lab replaced their 10 year old urinalysis system with the Siemens Automated
Urinalysis Workcell (AUWi). The AUWi combines the Siemens Atlas analyzer with a Sysmex
UF 1000i analyzer and a track system. The Atlas performs the biochemical testing of the 10
most common dipstick analytes. The UF 1000i performs the sediment analysis using both basic
flow cytometry and fluorescence flow cytometery. A separate reaction chamber is used for more
accurate measurement of bacterial counts. In laboratory reports from the new system, the CAST
parameter is used for reporting of Hyaline casts and the EPI parameter for reporting of
Squamous Epithelial cells. Other types of Casts are reported under Path Casts and other types of
Epithelial Cells are reported under Small Round Cells. Parameters such as crystals, yeast, oval
fat bodies, Trichomonas, mucus, or WBC clumping are reported under Additional Findings.
Coordination of the varied instrument modules in the AUWi system involves the use of a track
system for movement of specimens between modules and a dedicated computer with specialized
rules-based software. The system can be programmed to automatically validate and release
samples that fit within predefined laboratory criteria and to route samples for further urine
sediment analysis, based on user defined follow up testing criteria. Such automated operation
allows for faster turn-around-times of results.
The minimum volume to utilize these analyzers is 2.0 mL of urine. Please submit all samples in
a urine cup. These instruments cannot use grey top, urine preservative tubes. Testing is
available 24/7.
Tips for Packaging and Sending Specimens on Ice and Urine Cups
Samples on ice: Specimens for certain tests are to be sent to the lab on ice. Proper packaging
entails three bags: a securely closed bag of ice, the specimen in its own bag with placement of
both these bags into the third bag. Please do not send specimens placed directly on ice. Water
causes the label on the specimen to come loose from the container or to curl at the edges and
makes the information on the label difficult for laboratory instrumentation to read. This will
cause a delay in testing the specimen.
Urine cups: Before sending urine samples to the laboratory, be sure the lid is on securely and
the sample is double bagged. The laboratory continues to receive urine specimens that have
leaked in transit. Many times the lid has not been tightened properly. If a sample leaks outside
the carrier, the pneumatic tube system has to be shut down for cleaning, delaying all patient
testing.
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Change in CA 19.9 Assay
In a consolidation effort, Medical Labs has moved the CA 19.9 assay to a new instrument and
vendor. Results by the new assay are twice as high as the results of the old assay, on average,
but larger or smaller differences are seen in individual patients. Such differences between assays
cannot be eliminated by a correction factor; they reflect recognition of different epitopes by the
antibodies in the old and new reagents. The reference range for the new assay is < 37 U/mL.
To “rebaseline” a patient, please contact the laboratory at 4-LABS (924-5227) at the time you
order the test. The laboratory will perform and report results of both assays on the same sample.
The patient will be billed for only one test. Please contact the Chemistry Director on-call at pic
1657 or the Chemistry resident at pic 1267 if you have any further questions.
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