Tranfer a 10mL aliquot (minimum 4mL) to a Transfer vial/tube with cap - 12mL (LabCorp)
Liquid chromatography/tandem mass spectrometry (LC/MS-MS)
| Age | Reference range (μg/mg creatinine) | 
| 0 – 2 months | 0.0 − 35.0 | 
| 3 – 23 months | 0.0 − 32.6 | 
| 2 – 4 years | 0.0 − 22.0 | 
| 5 – 9 years | 0.0 − 15.1 | 
| 10 – 19 years | 0.0 − 12.8 | 
| >19 years | 0.0 − 7.6 |