Factor IX assay
The factor IX assay, also known as the antihemophilic factor B assay, can be run to test for activity of factor IX in blood. Diminished factor IX activity can indicate liver disease or vitamin K deficiency.
Tests are run on 1 ml of plasma and have an estimated turnaround time of 2-3 days.
Factor IX assays can be important in assessing for the presence of hemophilia in patients with blood clotting issues.