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Test Code LAB743 Protein/Creatinine Ratio, Urine, Random

Performing Laboratory

St. Louis Children's Hospital Laboratory - Chemistry

Specimen Requirements

Patient Preparation: None

Collection Container/Tube:

Preferred: Clean, plastic screw-cap urine collection container with no preservatives

Acceptable: Any clean, plastic collection container, no preservatives

Specimen Collection Volume: 5.0 (minimum 1.0 mL) urine

Submission Container/Tube: If specimen is coming from outside facility aliquot a minimum of 1.0 mL of urine into a plastic screw-capped tube for transport.

Special Instructions: Send to lab promptly.

Sample Rejection

Mislabled or unlabeled specimens

Logistics

Test Availability: Monday-Sunday

Cut-off time: None, performed as received

Turnaround Time: Same Day; 2 hours from receipt in performing lab

Reference Values

Reference Interval: 

Protein Ur Concentration: No reference intervals established
Creatinine Ur Concentration: No reference intervals established
Protein/Creat Ur Ratio  
     < 18 years: No reference intervals established
     ≥ 18 years: 0.0-180.0 mg/g Cr

Critical Value: None established

 

Methodology

Protein: Turbidmetric

Creat: Enzymatic Colorimetric

Limitations

  • NA

Additional Information

FOR SLCH CORE LABORATORY USE ONLY

Lab Processing Instructions: Mix well and aliqout minimum of 0.5 urine into a Roche-false bottom tube. If specimen is turbid or precipitates are present, mix well and aliquot into plastic container to centrifuge to clear then aliquot cleared urine into the Roche-false bottom tube for testing. 

Processed Volume: minimum 0.5 mL urine

Analyte Stability:

Specimen Type Temperature    Time
urine (no preservative)     Ambient 24 hours  
  Refrigerated     3 days 
  Frozen  1 month           

 

Test Classification and CPT Code

Creat Ur: 82570

Protein Ur: 84155

LOINC

in process

Last Reviewed

07/2025