Specimen Collection Manual and Test Catalog

2 mL serum or plasma; minimum 0.5 mL.

Allow serum to clot. Centrifuge to separate serum or plasma within 2 hours of collection.

Refrigerated (preferred). Room temperature or frozen specimen also acceptable.

Room temperature: 7 days. Refrigerated: 7 days. Frozen: 3 months.

Stability limits exceeded.

Less than 2 years: 0.1-0.4 mg/dL 
2 years to <6 years: 0.2-0.5 mg/dL
6 years to <10 years: 0.3-0.6 mg/dL 
10 years to <18 years: 0.4-1.0 mg/dL 
Females 18 years or older: 0.5-1.0 mg/dL 
Males 18 years or older: 0.6-1.2 mg/dL

Estimated Glomerular Filtration Rate (eGFR) is calculated based on the CKD-EPI 2021 equation. eGFR >=60 mL/min is considered normal in most case.

Creatinine, estimated GFR.

Creatinine with eGFR, creatinine with GFR, CREATB, Creatinine-S, Creatinine with estimated glomerular filtration rate

Serum creatinine is useful in the evaluation of kidney function and in monitoring renal dialysis. An estimated glomerular filtration rate (eGFR) will accompany all serum or plasma creatinine results.