Collect specimen in a blue top (citrate 3.2%) tube. Mix by inversion. Specimen should arrive at lab within 3 hours of collection; transport at room temperature. Alternatively, centrifuge, aliquot plasma into a plastic tube, and freeze the specimen within 4 hours of collection. Transport frozen specimen on dry ice. Collection of the blood through lines that have been previously flushed with heparin should be avoided. If the blood must be drawn through a VAD (vascular access device), the line should be flushed with 5 mL of saline and the first 5 mL of blood or six dead space volumes of the VAD discarded.

Please provide clinical history (brief description of the reason for testing, e.g., history of easy bruising and menorrhagia, family history of von Willebrand disease) and a listing of current and recent medications, including oral contraceptives, anticoagulants, and factor replacement therapy/DDAVP.