Mixing Study (APTT)
This test is used to distinguish specific ( factor VIII) and non-specific (lupus anticoagulant) inhibitors. It is used to determine heparin presence and detect single or multiple factor deficiencies. APTT Mixing studies can identify the cause of raised APTT. Contributing factors can include the presence of factor deficiency, lupus anticoagulant, heparin contamination or fibrinogen deficiency.
How to prepare for the test?
Overnight fasting is preferred. Give brief clinical history. Avoid Heparin for 1 day and Oral Anticoagulants for 7 days prior to test.