Required information: the anticoagulant type ( ie. unfractionated Heparin, Clexane, Fragmin, Rivaroxaban, Apixaban or Fondaparinux ) being monitored MUST be indicated on the request.

This information is required to select the correct assay.

Excerise great care in collection and handling of plasma to avoid the release of platelet factor 4 (PF4) which is a potent inhibitor of heparin.

3.5 mL Sodium Citrate tube filled to label marker, mixed by inversion and sent to laboratory immediately.

Do not use 1 ml citrate tubes.

If testing is delayed by more than 4 hours: spin separate and freeze plasma (plasma should be double spun)

Specimen rejection: specimens that are under or over filled , specimens that do not meet identification requirements.