HEMOCLOT ™ Quanti-V-L
A new clotting method for quantitating Factor V-Leiden in plasma
Hyphen Biomed presents a quantitative clotting method for Factor V-Leiden (FV L) measurement in citrated plasma, based on FV-L’s resistance to Activated Protein C (APC). Normal FV is not measured with the assay, as it is totally inhibited by APC, whilst FV-L keeps its clotting activity.
HEMOCLOTTM Quanti V-L (CK065K)
Diluted plasma is mixed with a purified clotting factor mixture, in a constant and optimised concentration, (R1 : Fibrinogen, Prothrombin, Protein S and APC). Purified FXa, with phospholipids (R2), is then added. Coagulation is initiated by the addition of calcium (Ca2+) and the clotting time (CT) is measured. The CT obtained is inversely proportional to the FV-L concentration. An inverse linear relationship is obtained between the CT and the FV-L concentration expressed as a percentage (%).Calibration
A standard curve is constructed using a FV-L heterozygous plasma pool as a calibrator.
- A totally quantitative assay for the measurement of FV-L concentrations on citrated plasma is presented.
- Only one clotting test is required (= no problem of result interpretation).
- Excellent discrimination (for both clotting times and FV-L concentrations) between normals, heterozygous and homozygous patients (for the R506Q mutation ).
- Patients with low concentrations of total FV clotting activity (<25%) must be identified, and the diagnosis confirmed by comparing FV-L and total FV clotting activity (normals < 0.1).
- No interference of Heparin or Dicoumarol therapy.
- Easy to perform, cost effective and reliable assay, fully automatable on laboratory instruments.
Factor V-Leiden concentrations in normals and patients carrying the FV-L (R506Q) mutation:
|Patients||FVL Conc. (%)||CT* (sec)|
|HETEROZYGOUSZ(N=8)||35 – 60||50 – 70|
*CT may vary from lot to lot, but FV-L concentrations are accurately determined by using the calibration curve specific for each lot and each run.
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