Cystatin C
Cystatin C-14224
Since it is formed at a constant rate and freely filtered by the healthy kidney, cystatin C is a good marker of renal function. Serum concentrations of cystatin C are almost totally dependent on glomerular filtration rate (GFR). A reduction in GFR causes a rise in the concentration of cystatin C.
Immediately following collection, thoroughly mix sample by gently inverting 5 times
- Allow sample to clot for a minimum of 30 minutes
- Spin within two (2) hours of sample collection
Gold serum separator (SST) tube
Dk green:
Immediately following collection, mix sample thoroughly by gently inverting 8 - 10, times to prevent clotting
Red:
- Allow sample to clot
- Spin
- Transfer serum to a Transfer vial/tube with cap - 12mL (LabCorp), labelled as serum, within two (2) hours of sample collection
Dk green:
- Spin
- Transfer plasma to a Transfer vial/tube with cap - 12mL (LabCorp), labelled as the appropriate plasma type, within two (2) hours of sample collection
Ambient (preferred) - 14 days
Refrigerated - 14 days
Frozen - 14 days
Freeze/thaw cycles - stable x 3
- Specimens other than serum or heparinized plasma
- Gross hemolysis (>1,000 mg/dL Hgb)
- Excessive turbidity
- Clots in samples
Turbidimetric (directly traceable to ERM-DA471/IFCC, the international standard reference material)
|
Age |
Reference range (mg/L) |
|
0 – 1 year |
Not established |
|
2 – 50 years |
0.60 - 1.00 |
|
51 – 60 years |
0.67 - 1.14 |
|
61 – 70 years |
0.72 - 1.16 |
|
71 – 80 years |
0.78 - 1.15 |
|
>80 years |
0.87 - 1.12 |