Description:
RoxFactorIX isachromogenicassaykitbaseduponFXagenerationforthedeterminationofFactorIX(FIX)activityinFIXpreparations,includingpotencyassignmentofFIXconcentrates.
FordeterminationofFactorIXactivityin plasma andFactorIXpreparations,includingpotencyassignmentofFIXconcentrates.
- NouseofFIXdeficiencyplasma
- Detection Limit:0.1% FIX(CLSIEP17-A)
- QuantificationLimit:0.5%FIX(CLSIEP17-A)
- Linearity:0.5–200%(CLSIEP06-A)
Kitcomposition:
ReagentA(2vials)
ReagentAcontainslyophilizedhumanFVIIIandhumanFX.Reconstitutewith1.4mlwater.Allowtostandfor5minat20-25°Cwithintermittentgentlemixingforcompletereconstitution.- ReagentB(2vials)
ReagentBcontainslyophilizedbovineFXIa,calciumchlorideandphospholipids.Reconstitutewith8.0mLwater.Allowtostandfor5minat20-25°Cwithintermittentgentlemixingforcompletereconstitution. - FXaSubstrate,5mL(1vial)
LiquidsolutionofchromogenicFXasubstrate(Z-D-Arg-Gly-Arg-pNA),2.5mmol/l,containingathrombininhibitor.Readytouse. - FIXDiluentBuffer,StockSolution,20mL(1vial)
Liquidstocksolutionofdiluentbuffer.Beforeuse,dilute1+9withwatertoobtaina0.025mol/lTris-HClbufferworkingsolution,pH7.9,with1%bovineserumalbumin.
Note:AllreconstitutionsanddilutionsshouldbemadewithwaterofaqualityofatleastNCCLSTypeIIwater.
MeasurementPrinciple:
FIXactivityisdeterminedinachromogenicmethod,inwhichhumanFIXisactivatedbybovineFXIaandwhereformedFIXaactivateshumanFXinthepresenceofhumanFVIII,calciumionsandphospholipid.Similartoinvivoconditions,FVIIIisactivatedbythrombinwhichisgeneratedduringtheincubation.TheamountofFXaformedisdeterminedfromthehydrolysisofachromogenicFXasubstrate.TheFIXactivityofthesampleisassignedvs.aFIXconcentratestandardwithFIXpotencyexpressedinInternationalUnits(IU).
Background:
FIXactivityinplasmaandconcentratesiscurrentlydeterminedwithclottingmethods.Theaccuracymaybecompromisedduetolow-resolutiondose-responsecurves.NewrFIXvariantsmaybeachallengeregardingsuitABIlityofclottingmethods.
