Cleveland Heartlab P, Test

CPT Code: 80185
Order Code: C2354
ABN Requirement: No
Synonyms: Dilantin; Diphenylhydantoin
Specimen: Serum
Volume:  1.0 mL
Minimum Volume:  0.5 mL
Container: Red Top (no gel barrier) tube


  1. Collect and label sample according to standard protocols.
  2. Gently invert tube 10 times immediately after draw. DO NOT SHAKE.
  3. Allow blood to clot 30 minutes.
  4. Centrifuge for 10 minutes.
  5. Aliquot serum into a labeled transport tube and cap tightly.

Special Instructions:  Do not collect in gel separator tube. Draw once steady state is achieved.

Transport: Store specimen at 2°C to 8°C after collection and ship the same day per packaging instructions included with the provided shipping box.


Ambient (15-25°C): 4 days
Refrigerated (2-8°C): 4 days
Frozen (-20°C): 30 days

Causes for Rejection: Improper labeling; samples not stored properly; samples older than stability limits; SST (gel barrier) tube

Methodology: Kinetic Interaction of Microparticles in a Solution

Turn Around Time: 2 to 3 days

Reference Range:

Age ug/mL
All Ages 10.0-20.0

Urgent Values:

Age ug/mL
All Ages >40.0

Clinical Significance: The test is performed to monitor the concentration of phenytoin in the blood.

The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.