Antithrombin III Activity

Supply #T04 - Light Blue 2.7mL

Test code: 216

Methodology: Chromogenic

Clinical Significance: Aids in the detection of hypercoagulable states associated with venous thrombotic episodes. May be useful in patients who apprear to be hyporeponsive to heparin.

Includes: Antithrombin III Activity

Alternative Name(s): Antithrombin III Functional; AT-3 Activity; AT3

Collection Guide: 

Supply: T04 - Light Blue 2.7mL

A completely filled tube is necessary because the correct ratio of blood to citrate is critical (9:1). Mix by gentle inversion 3-4 times.

Preferred Specimen: Platelet Poor 3.2% Sodium Citrate-antigcoagulated Plasma

Preferred Volume: 2.7mL

Instructions: A completely filled tube is necessary because the correct ratio of blood to citrate is critical (9:1). Mix by gentle inversion 3-4 times. Centrifuge to separate plasma from cells. Remove plasma immediately and freeze

Coagulation specimen collection requirements:

A light-blue top tube (containing 3.2% sodium citrate) that will be used for coagulation testing must be filled to completion. Please see the attached BD guides for instructions. Under-filling the tube changes the ratio of blood to anticoagulant additive. The under-filled tube will be considered an improper specimen.

Specimen must reach the band etched into the tube – it is critical that that band is reached by the specimen. The position of the label and any markings on it are immaterial – that etched band is the goal.

If a winged blood collection device (butterfly) is used to collect a light-blue top tube for coagulation studies, a waste tube must be drawn first. The waste tube must also be a light-blue top tube or a tube that contains no additives. This waste tube is drawn first to remove the air in the tubing of the winged collection device. Once blood flows through the tubing, the waste tube can be removed and discarded. The waste tube does not need to be completely filled. If the air is not displaced from the tubing into a waste tube, it will be drawn into the specimen tube and cause a short-fill of the tube. Less volume of blood in the tube alters the required blood-to-anticoagulant ratio needed for coagulation studies. The under-filled tube will be considered an improper specimen.

Expired tubes lose their vacuum and will not pull enough blood into the tube for the correct blood-to-anticoagulant ration. The under-filled tube will be considered an improper specimen.

Special Instructions: DO NOT REFREEZE SAMPLES

Transport Container: Pour off Tube

Transport Temperature: Frozen

Specimen Stability: Frozen: 1 week

Reject Criteria:

  • Short Draws
  • Overdraws
  • Clotted Samples

For additional supply or collection device information, please contact DLO's Customer Service at (800) 891-2917, option 2.