Chemistry Specimen Processing

Analyte	Specimen Type	Collection Media	Collection Notes	Reference Interval
Creatinine	Urine, 24 hour
	Blood serum	Lithium heparin
Urea	Blood serum or plasma	Lithium heparin		2.1 - 7.1 mmol/L
	Urine, random		Use thymol preservative and refrigerate
	Urine, 24 hour		Use thymol preservative and refrigerate	430 - 710 mmol/day
Uric Acid	Blood serum or plasma	Lithium heparin
	Urine, 24 hour
Urinalysis	Urine, first morning midstream clean-catch preferred		Fresh samples <2h old