Test directory: Factor VIII Inhibitor Assay

Ordering Code5651
Test NameFactor VIII Inhibitor Assay
AliasFactor VIII Bethesda Assay
Preferred SpecimenPlasma
Preferred ContainerCitrate, 3.2% (Lt Blue)
Other Specimen/ContainerWhole Blood in Citrate, 3.2% (Lt Blue) if testing is done within 4 hours.
Optimum VolumePlasma = 1.2 mL
Whole Blood = Entire tube
Collection InstructionsDraw full tube
Mix tube well
Handling InstructionsDouble centrifuge plasma, separate, and freeze at -20 deg. C immediately. Do NOT thaw once specimen is frozen.
Transport RequirementsPreferred method of transport is frozen plasma.
Specimen StabilityAmbient: 4 hours Whole Blood (unopened tube)
Ambient: 4 hours Plasma
Frozen: 2 weeks Plasma
Rejection CriteriaClotted, Contaminated, Hemolyzed,
Improperly filled or underfilled tube,
Specimen older than stability limits.
Avail. StatNO
Analytic Time1 Day
MethodologyClot Detection

Reference range(s)

ComponentAgeMale NormMale Critical LowMale Critical HighFemale NormFemale Critical HighFemale Critical LowUnitsAdd'l info
Factor VIII ActivityALL50-20050-200%
Bethesda UnitsALL<=0.3<=0.3BU