URINALYSIS – MICROSCOPIC EXAMINATION
Document Number:
Pro68-11
Effective (or Post) Date:
20 Nov 2008
Document Origin
Company:
MU-JHU Lab
SMILE Approved by:
Jo Shim
Review by
Heidi Hanes
Review date
7 Feb 2012
SMILE Comments: This document is provided as an example only. It must be revised to accurately reflect
your lab’s specific processes and/or specific protocol requirements. Users are directed to countercheck facts
when considering their use in other applications. If you have any questions contact SMILE.
Author: Ali Elbireer
CORELAB, MU-JHU RESEARCH COLLABORATION
URINALYSIS – MICROSCOPIC EXAMINATION
Procedure: Urinalysis Microscopic Examination SOP
ffective Date:
Jun 05, 2005
Revision #2
Supersedes Rev# 1
April 03, 2003
Revised/Prepared By
Signature
Date
Signature
Date
Signature
Date
Ali Elbireer
Approved By
Laboratory Medical Director
Laboratory Administrator
Annual Review By
(Lab Supervisor/Lab Management)
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Rev 2.0
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CORELAB, MU-JHU RESEARCH COLLABORATION
URINALYSIS – MICROSCOPIC EXAMINATION
1. Principle
The microscopic examination is a vital part of the routine urinalysis. It is a valuable diagnostic tool for the
detection and evaluation of renal and urinary tract disorders as well as other systemic diseases. Urine Microscopy
will only be performed per physicians/primary care-giver request for clinical management or per study protocol
requirements.
2. Specimen Collection and Handling
2.1.
2.2.
2.3.
2.4.
Patient Preparation: none for random, first-morning or post-prandial urine
Specimen Requirements: fresh, cleanly voided urine collected in a clean container
Specimen Volume: Optimum 20 mL, minimum 1 mL
Specimen Handling: Test as soon as possible after collection.
2.4.1. Optimum conditions: test within 1 hour of collection.
2.4.2. Option: refrigerate at 2-80C immediately and test within 12 hours.
2.4.3. Marginal: test upon receipt, note if specimens are un-refrigerated and >4 hours old.
3. Materials Required
3.1.
3.2.
3.3.
3.4.
3.5.
Conical centrifuge tube, 15 mL
Microscope slides
Microscope cover slips
Plastic disposable pipette
Urine Controls, Hematronix Level 1 and 2 or equivalent
4. Equipment Required
4.1. Microscope
4.2. Centrifuge, 2000 rpm
5. Reagent Preparation – none
6. Storage and Stability
6.1. Hematronix Controls
6.1.1. Unopened product is stable up to the expiration date printed on the label when kept at 2-80C. Do
not freeze.
6.1.2. Opened stability is 2 weeks at either 2-80C or 18 - 300C.
6.1.3. Do not store the control material in direct light.
6.1.4. Discard the controls if turbidity or evidence of microbial contamination is present.
6.1.5. Note: It is normal to observe cellular sedimentation in the bottom of the tube when stored for
prolonged period.
7. Calibration – none
8. Quality Control
8.1.
8.2.
8.3.
8.4.
8.5.
8.6.
Run two (2) control levels each day of use.
Check the lot numbers / expiration dates of the controls are listed on the QC log and are current.
Record control values on QC log and check that the results are within the expected range.
If the QC results fall within the expected range, continue with patient testing.
If the QC results are not within range, repeat and consult with the LS/LSA for further action.
Document any QC problems or unexpected results on the Corrective Action Log.
9. Procedure
9.1. Note the color, clarity and volume of urine and record on the urinalysis worksheet.
9.2. The microscopic examination should be performed on a 10-15 ml centrifuged sample.
9.2.1. Mix the sample well and pour 10-15 mL into a 15 mL conical centrifuge tube.
9.2.2. Centrifuge at 2000 rpm for 5 minutes.
9.3. If the volume of specimen is too small to be centrifuged (< 0.5 mL)
9.3.1. Examine the sample directly.
9.3.2. Report the results are from an un-centrifuged urine under comments as <0.5 mL, direct exam”
9.4. If the volume of the specimen is <10 mL but > 0.5 mL, centrifuge the sample and report as “short
sample, <10mL” under sample comments.
9.5. Pour off the supernatant fluid and re-suspend the sediment in the urine that drains back down the sides of
the tube.
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URINALYSIS – MICROSCOPIC EXAMINATION
9.6. Flick the bottom of the tube to mix the sediment.
9.7. Using a disposable pipette, place a drop of the sediment on a clean slide and cover with a coverslip.
9.8. Examine immediately using subdued light to provide adequate contrast (partially close the iris
diaphragm and adjust the condenser).
9.8.1. If the light is too bright, low refractive index objects such as casts could be missed.
9.9. Use the fine adjustment continuously (adjust up and down) to see the depth of the object(s) as well as
other structures that may be on a different focal plan.
9.10. First view the sediment under low power (10x).
9.10.1. Scan the slide and observe for casts, crystals and other elements that may be present.
9.10.2. Switch to high dry power (40x) when necessary to delineate the structures that are seen.
9.10.3. Casts have a tendency to move towards the edge of the coverslip; scan the periphery of the
coverslip as well.
9.10.4. Note the type and the average number of casts seen per low power field on the worksheet.
9.10.5. Note the presence and type of crystals (crystals need only be reported as present unless they are
very abundant).
9.11. View the sediment under high power (40x)
9.11.1. Estimate the number of red blood cells, white blood cells and epithelial cells per high power
field by observing 10-15 fields.
9.12. Note any bacteria or yeast (budding or hyphae) and estimate the amount as follows:
1+ approximately 0-25% of the field
2+ approximately 25-50% of the field
3+ approximately 50-75% of the field
4+ full field
9.13. Note any Trichomonas vaginalis seen and estimate the number per field (0-1, 0-3 etc).
9.14. Note any other organisms or objects seen such as glitter cells or clue cells.
9.15. Record the results obtained on the urinalysis worksheet, microscopic section.
10. Expected Values
10.1. Color: Straw to dark yellow
10.2. Clarity: Clear to hazy.
10.3. Casts: None seen.
10.4. WBC’s: 0-3/hpf
10.5. RBC’s: 0-3/hpf
10.6. Epithelial cells: 0-3/hpf
10.7. Crystals: None Seen
10.8. Organisms (bacteria, yeast, trichomonas): None seen.
10.9. Glitter (WBC covered with bacteria) or Clue (epithelial cell covered with bacteria) cells: None seen.
11. Procedural Notes
11.1. If cleanly voided urine is not collected, the microscopic examination may give erroneous results due to
the presence of external organisms/artifacts.
11.2. Specimens left at room temperature will begin decomposing due to presence of bacteria and pH changes.
Casts and other objects/organisms may be lost.
11.3. Crystals are usually not found in freshly voided urine but appear after the urine stands for awhile.
11.4. Many of the crystals that are found in the urine have little clinical significance except in cases of
metabolic disorders, calculus formation and the regulation of medication.
11.5. Casts are always renal in origin, and they are important indicators of intrinsic renal disease.
11.6. Casts are reported according to type and the number that is present per low power field (10x)
11.7. The accuracy of microscopic identification must be checked by correlation with the macroscopic (i.e.,
dipstick results), such as the presence of:
11.7.1. Turbidity with Bacteria
11.7.2. Protein with casts,
11.7.3. Positive blood with red cells (RBC)
11.7.4. Positive leukocyte esterase with white cells (WBC)
Note: to ensures that all personnel report microscopic morphologic data on patient samples in a similar fashion.
For initial accuracy, as well as consistency in serial samples from the same patient, all staff should be consistent
with respect to morphologic classification reporting, to accomplish this we will utilize the numeric reporting
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URINALYSIS – MICROSCOPIC EXAMINATION
system of 1+, to 4+ (described above# 9.12) and we will use the CAP urine sediment photomicrographs to ensure
all staff review and able to identify Urine microscopy.
12. References
12.1. A Handbook of Routine Urinalysis, Sister Laurine Graft, JB Lippincott Company, ISBN 0-397-52111-1.
12.2. Clinical Diagnosis and Management by Laboratory Methods, 19th Edition, John Bernard Henry, MD,
WB Saunders, ISBN 0-7216-6030-4.
12.3. CAP Reference Notebook: Urine, Body Fluids and Misc.
12.4. Urinary Sediment, A Textbook Atlas, Meryl H. Haber, ASCP Press, ISBN 089189-103-X.
13. Appendix
13.1. Urinalysis Worksheet
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