4. Rationale of Urine testing
• (Relatively) readily collected
and easily available specimen
• Contains information about the
body’s major metabolic fxns
• inexpensive
5. Rationale of Urine testing
? Disease conditions
? Hormonal activity
? Ruling out, ruling in,
screening & prognosis
6. Urine Composition
• How do the ff. affect composition:
–Dietary intake
–Physical activity
–Body metabolism
–Endocrine functions
–Body position
10. Specimen
• What was used in the collection?
– answered by COLLECTION TECH / MTD
• When was the specimen collected?
– answered by TYPE OF SPECIMEN
• What are the criteria for acceptance &
rejection of specimen for processing &
analysis?
• What is meant by QNS & COC?
• Patient preparation?
11. Collection technique / method
1. Bottle method
a. Routine void
b. Midstream clean catch
c. Drug testing
2. BD Vacutainer (gray, cherry red & yellow stopper)
3. Gauze method / pediatric bag
4. Catheterization
5. Suprapubic aspiration
12. Collection technique / method
1. Wash hands thoroughly. Do not open the sterile container
until it is absolutely necessary.
2. Wash the vulva and surrounding area with soap and water.
3. Begin urinating into the toilet and stop after a few drops.
4. Position the container to catch the middle portion of the
stream. Make sure that at least ¾ of the container has been
filled up.
5. Urinate the remainder into the toilet.
6. Securely & immediately replace the cap without touching the
inside rim of the container.
16. Physical changes
Color
• Due to oxidation or reduction of substances
Clarity
• Falsely decreased
• Due to bacterial proliferation, solute ppt’n
Odor
• Falsely increased
• Due to bacterial proliferation
17. Chemical Changes
pH
• Falsely increased
• Due to bacterial decomposition of urea to
ammonia
• Falsely decreased
• Due to bacterial or yeast conversion of glucose
to form acids
18. Chemical Changes
glucose
• Falsely decreased
• Due to cellular or bacterial hydrolysis
ketones
• Falsely decreased
• Due to bacterial metabolism of acetoacetate to
acetone
• volatilization of acetone
19. Chemical Changes
bilirubin
• Falsely decreased
• Due to photo-oxidation to biliverdin and
hydrolysis to free bilirubin
urobilinogen
• Falsely decreased
• Due to oxidation to urobilin
20. Chemical Changes
Nitrite
• Falsely increased
• Due to bacterial production following spx
collection
• Falsely decreased
• Due to conversion to nitrogen
21. Microscopic Changes
RBC, WBC, casts
• Falsely decreased
• Disintegration of cellular & formed elements,
esp in dilute alkaline urine
Bacteria
• Falsely increased
• Due to bacterial proliferation ff spx collection
22. Preservation
WHY IS IT NECESSARY TO:
• Maintain the pH?
• Avoid bacterial contamination?
• Avoid conversion of urea to ammonia?
HOW DO YOU ACCOMPLISH THE
AFOREMENTIONED STEPS?
