Test directory: Phenytoin/Free Phenytoin

Ordering Code5454
Test NamePhenytoin/Free Phenytoin
AliasFree Dilantin
Free Phenytoin
Preferred SpecimenPlasma
Preferred ContainerLithium Heparin PST (Green)
Other Specimen/ContainerSerum in Plain (Red), Serum in SST (Gold)
Optimum Volume2 mL
Handling InstructionsSend aliquot if transport time >24 hours.
Transport RequirementsOahu: Ambient
Airline: Ambient
Specimen StabilityAmbient: 4 Days
Refrigerated: 4 Days
Frozen Serum: 1-2 Months capped at -20 C
Frozen serum samples should be thawed only once. Test cannot be added to >24 hours, unaliquoted specimens
Do not freeze Lithium Heparin Plasma.
Rejection CriteriaGrossly hemolyzed, Insufficient quantity, Specimen older than stability limits, Uncentrifuged gel separator tube specimens >2 hours old, Unaliquoted gel separator tube specimens >24 hours old, Frozen Lithium Heparin plasma
Avail. StatYES
Analytic Time1 Day
MethodologyKinetic Interaction of Microparticles in Solution (KIMS) /
Fluorescence Polarization Immunoassay (FPIA)

Reference range(s)

ComponentAgeMale NormMale Critical LowMale Critical HighFemale NormFemale Critical HighFemale Critical LowUnitsAdd'l info
DilantinALL10.0-20.0>= 30.010.0-20.0>= 30.0ug/mL
Free PhenytoinALL1.0-2.0>= 3.01.0-2.0>= 3.0ug/mL