Specimen Requirements

Container/Tube:

Preferred: Green-top (lithium heparin) tube

Acceptable: Gold-top serum gel tube, plain red-top tube, EDTA plasma
Minimum Specimen Volume:  9 µL plus a dead volume

Stability: Samples may be stored at room temperature for 5hours or at 2 – 8°C for 12 hours . For longer storage, samples may be frozen at -20°C for up to 3 months.

Note:  This assay is affected by biotin interference.  Venipuncture should occur prior to sulfasalazine and/or sulfapyridine administration due to the potential for falsely depressed results.