Factor IX assay

Factor IX Assay

A factor IX assay (sometimes called a clotting factor assay) is a medical test that measures the activity of coagulation factor IX in a sample of blood or plasma. This test is part of a battery of tests, often referred to as coagulation tests, used to help diagnose and manage bleeding problems.

Preparation for Factor IX Assay

In most cases, no fasting or other special preparation is required prior to having a factor IX assay. If taking anticoagulant medication such as warfarin (Coumadin), the doctor may direct the patient to discontinue the medication prior to the test.

Procedure for Factor IX Assay

During the factor IX assay, a sample of blood is obtained and sent to a laboratory for analysis. In the laboratory, the plasma is separated from the red blood cells and placed into a test tube. A buffer is added to the sample which prevents the coagulation factors from clotting too quickly. Then the activity of factor IX is measured and the results reported as a percentage of normal factor IX activity.

Types of Factor IX Assay

The most common type of factor IX assay is the activated partial thromboplastin time (APTT). This method measures factor IX activity by measuring the time it takes for coagulation factors to form a clot in the sample. Other types of factor IX assay that measure the activity of factor IX are chromogenic assays and enzyme-linked immunosorbent assays (ELISA).

Risks of Factor IX Assay

The risk associated with factor IX assay is minimal. The only risk involved in obtaining a sample of blood is the potential for bleeding complications if the sample is not taken properly.

Why is Factor IX Assay Important?

Factor IX assay is important because it helps to diagnose and monitor clotting disorders. By measuring the activity of factor IX in the blood, a doctor can determine whether the clotting process is working normally or if there is a deficiency or abnormal activity of factor IX present. This can help to identify the underlying cause of a patient’s bleeding disorder and help the doctor to develop an appropriate treatment plan.

When is a Factor IX Assay Used?

A factor IX assay is typically ordered when a patient is experiencing signs and symptoms of a clotting disorder. The most common symptom of a clotting disorder is abnormal or prolonged bleeding. This may be accompanied by bruising or other signs of an underlying condition. In some cases, a factor IX assay may also be ordered as a routine screening test to help diagnose certain clotting disorders.