CLINICAL LAB SCIENEC

296
ESSENTIALS OF CLINICAL LABORATORY SCIENCE
In the Lab
Procedural Alert
Critical Specimen Requirements
for Accurate Testing
1. Collect a random fresh
urine sample and a control
specimen to insure
accurate results.
2. Perform test as soon as
possible.
3. Urine sample is stable at
room temperature for 1
hour and refrigerated for
4 hours. If refrigerated,
allow urine to sit at room
temperature for 15 minutes
before testing.
4. Minimum volume needed
is 1 mL.
BASIC URINALYSIS AND BODY FLUIDS ANALYSIS PROCEDURES
Urinalysis is a useful indicator of health or disease, especially in the areas of
metabolic and renal disorders. Urine undergoes many changes during states
of disease or body dysfunction. These changes may be evident even before
blood composition is altered to a significant extent. In addition, laboratory procedures
for some of the other body fluids are performed in the same manner
as for urine samples, so cerebrospinal fluid (CSF) is included in this chapter.
Patients for whom urinalysis is needed should be instructed in how to
properly collect a urine specimen for testing. The testing procedures should be
performed as quickly as possible following the collection of a sample to avoid
bacterial growth and breakdown of formed elements in the sample. If necessary,
the specimen should be refrigerated until it can be tested. A urine sample is
stable at room temperature for 1 hour or refrigerated for 4 hours. If refrigerated,
allow urine to sit at room temperature for at least 15 minutes before testing.
URINALYSIS AND BODY FLUIDS ANALYSIS PROCEDURE #1
Physical and Biochemical Testing of Urine
Principles
Urine dipstick testing is a screening test performed on fresh urine. A chemical-impregnated
reagent strip is dipped in fresh urine to determine glucose,
bilirubin, ketones, specific gravity, blood, pH, protein, urobilinogen, nitrites,
and leukoesterase.
Interfering Substances
Abnormal urine color may affect the readability of the reagent areas on the urinalysis
reagent test strip. Such urine specimens should be sent to the urinalysis department
of the clinical laboratory.
Equipment and Supplies
1. Gloves, disposable paper towels, and disinfectant or other cleaning solution
2. Report form for urinalysis results (Procedure Report Form)
3. Fresh urine sample, preferably clean catch or catheterized, of at least 10 mL
4. Test tubes and test tube rack
5. Container with biochemical dipsticks and chart for manual reading (urine strip
reader may be used if available)
6. AO TS Meter or urinometer to confirm reagent strip results if necessary
7. Normal and abnormal urine controls
8. Electronic timing device or clock/watch with second hand
9. Procedures #3 through #6 are used for confirming biochemical results
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