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Test ID TACPK Tacrolimus, Peak, Blood

Useful For

Assessment of postdosing (peak) blood tacrolimus concentrations

Method Name

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

Reporting Name

Tacrolimus, Peak, B

Specimen Type

Whole Blood EDTA

Necessary Information

Date of last dose, time of last dose, and dosage information are required.

Specimen Required

Container/Tube: Lavender top (EDTA)

Specimen Volume: 3 mL

Collection Instructions:

1. Do not centrifuge.

2. Send whole blood specimen in original tube. Do not aliquot.

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole Blood EDTA Refrigerated (preferred) 14 days
  Ambient  14 days
  Frozen  14 days

Reference Values

5.0-30.0 ng/mL


Target steady-state trough concentrations vary depending on the type of transplant, concomitant immunosuppression, clinical/institutional protocols, and time posttransplant. Results should be interpreted in conjunction with this clinical information and any physical signs or symptoms of rejection or toxicity.

Day(s) Performed

Monday through Sunday

Report Available

2 to 4 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
TACPK Tacrolimus, Peak, B 59822-7


Result ID Test Result Name Result LOINC Value
88157 Tacrolimus, Peak, B 59822-7
DAT7 Date of last dose 29742-4
TM01 Time of last dose 29637-6
DOSE1 Dose, mg 32594-4


If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.