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|Approval req'd?||Yes, if testing is requested between midnight and 8:00 AM.|
|Performed by||Parnassus Chemistry|
|In House Availability||Test available 7 days per week from 8:00 AM to midnight only.|
|Method||Spectrophotometric, kinetic (alkaline picrate,Jaffe) assay on Beckman DXC 600/800 analyzers. Calibration traceable to isotope dilution mass spec (IDMS) standardization
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|Collection Instructions||Submit serum (Gold top) drawn within 24 hours of urine collection-preferably within the interval of collection.
Give the weight in kg and height in cm of the patient if a corrected clearance is needed.
Refrigerate the collection container during the collection period.
|Container type||24 hour urine collection container AND Gold top
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|Amount to Collect||Entire 24 hour urine output and
2 mL blood (Gold top)
|Sample type||24 hour urine collection or timed urine AND serum|
|UCSF Rejection Criteria||Container not refrigerated during collection|
Pediatric reference ranges from Holliday, Malcolm A; Barratt, T. Martin and Vernier, Robert L. Pediatric Nephrology, 2nd edition Williams & Wilkins and Edelmann, Chester M. Jr. Pediatric Kidney Disease vol 1, Little Brown & Company, Boston MA. Adult reference ranges from Tietz Textbook of Clinical Chemistry 2nd edition,W.B. Saunders Company
|Stability||Refrigerated 2 days|
|Turn around times||4 hours|
|Additional information||Note: Clearances are often inaccurate because of incomplete urine collection. A 4- or 6-hour collection is likely to be more complete than the classic 24 hour test, but extrapolation of results from shortened collections may not be accurate.
GFR can also be estimated from serum creatinine measurements without the need for urine creatinine measurements. See the laboratory manual entry on serum creatinine for details on estimating GFR from serum creatinine results.
|Last Updated||4/13/2012 2:21:50 PM|
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