Creatine and Creatinine, 24-Hour Urine

CPT Test code: 82540;82570

Test Includes:	Creatine, urine; creatinine, urine; creatine:creatinine ratio; eGFR calculation
Related Information:	Urine Specimens
Specimen:	Urine (24-hour), frozen
Volume:	10 mL aliquot
Minimum Volume:	1 mL aliquot
Container:	Plastic urine container
Special Instructions:	State patient’s sex and 24-hour volume on the test request form.
Collection:	Collect 24-hour urine, no preservative. Mix well.
Storage Instructions:	Freeze
Causes for Rejection:	Thawed creatine specimen; 6N HCl, boric acid, or alkali added to collection (Acid or alkali preservative will convert creatine to creatinine, falsely lowering creatine values.)