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Test Code Lab876 Tacrolimus (FK506), Blood

Performing Laboratory

Barnes-Jewish Hospital Laboratory

Methodology

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Specimen Requirements

Specimen Type: Whole blood
Container/Tube: Lavender top (EDTA)-Separator gel tube is not acceptable.

Specimen Volume: Full tube

Collection Instructions:

Do not centrifuge.

1. Draw blood for trough level immediately prior to next dose.

2. Label specimen appropriately (peak, trough, random).

Additional Information: Date and time of draw are required.

Day(s) Test Set Up

Monday through Sunday

Cut-off time: 2330, 0600, 0900, 1200, 1530

Turnaround Time:
STAT: not available

Routine: 3 hours after cut-off time

Test Classification and CPT Coding

80197-Each

Reference Values

Results are reported in ng/mL.
The therapeutic range for tacrolimus can vary by transplant organ type and sample timing but a trough range of 5 - 15 ng/mL is typical.

Specimen Transport Temperature

Ambient

Additional Information

For BJH Laboratory Use Only

Alternate Tube(s):

1 pediatric, lavender-top (EDTA) tube

 

Analyte Stability:

  • Specimens must be processed within 7 days.
  • Processed sample stability:
    • Ambient - 7 days
    • Refrigerated (2 - 8°C) - 7 days
    • Frozen (≤ -20°C) - 2 weeks

Mix freshly collected, refrigerated, or thawed specimen thoroughly prior to use. Avoid repeated freezing and thawing.

  • See Analyte Stability Chart under General Information for a complete list.

 

 

Laboratory Processing Instructions:

Test performed in BJH Core Lab.  Log in and place in the pending specimen refrigerator. Do not centrifuge. Do not freeze. Completed specimen is stored refrigerated for 5 days.

LOINC Code Information

Name LOINC Code
Tacrolimus 74097-7
Tacrolimus Trough 77348-1