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Test Code TacrBldSp Tacrolimus Level Blood Spot

Important Note

This test is best suited for stable, outpatients.  Exceptions for inpatients need approval from Chemistry Medical Director.

Clinical System Name


Tacrolimus Level Blood Spot




Sample Requirements

Specimen: Capillary blood

Container(s): Dried blood spot card

Preferred Vol: 3 full circles

Minimum Vol:  1 full circle


Note: Draw 30 minutes to 1 hour before next dose. For line or peripheral collections, order Tacrolimus Level (not Blood Spot and collect in an EDTA tube. 


Processing Instructions

Reject due to

Spin: N

Aliquot: N

Temp: RT

Storage location: Store specimen and labels in the Biochemical Genetic box.


Off-site collection: Draw 30 minutes to 1 hour before next dose. Note draw time on the requisition. For capillary collection, spot 3 full circles on dried blood spot collection card, allow to air dry for 3 hours, and submit (or mail) to laboratory.  See instruction sheet for collection details below.


Temperature Time
Room temp 4 w
Refrigerated 4 w
Frozen 6 m



STAT Performed TAT
N M,W,F (run overnight, result available next day) 2 - 4 d

Specimen must be received in the lab by 10:00 for next day results.

Performing Laboratory

Seattle Children's Laboratory    



Department:  Chemistry

Location: Chem West

Phone Number: (206)987-2617




CPT Codes



Method: LC/MS/MS

Analytical Volume: 6 mm diameter circle


Reference Range

5 - 17 ng/mL