Therapeutic drug management
Trough levels are most reproducible
Dk green heparin (Li or Na), no gel
Immediately following collection, mix sample thoroughly by gently inverting 8 - 10 times to prevent clotting
Refrigerated (preferred)
Ambient - 3 days
Frozen (OK)
Gel-barrier tubes are not recommended
Immunoassay (IA)
5.0 -12.0 µg/mL
>24.0 µg/mL