This is the first-line test for heparin antibodies in patients with suspected heparin-induced thrombocytopenia (HIT).

Lt blue Sodium citrate (Na Cit) - 2.7mL

If the patient has a hematocrit >55, a specially prepared Lt blue Sodium citrate (NaCit) tube must be used in place of the standard Lt blue Sodium citrate (NaCit) tube.

Hematocrit-Anticoagulant adjustments

• Do not over or under fill tube as the ratio of anticoagulant to whole blood is critical

Coag – tube fill guidelines

• Immediately following collection, mix sample thoroughly by gentle inverting 8 - 10 times, to prevent clotting

• Process Platelet Poor Plasma (P.P.P)

  • Coag – how to prepare a specimen for special coagulation testing

• Transfer plasma into an aliquot tube, using a spot label "NaCit Plasma P.P.P" to label as platelet poor plasma
• Freeze immediately

Microcentrifuge vial/tube in a Snap cap conical vial/tube and cap (Beaker sites)

Coagulation specimen transport vial/tube  (all other sites)

Frozen (strict)

Refrigerated - NO

• Specimens collected in Grenier tubes 
• Improper label (unlabeled or mislabeled)
• Improper anticoagulant
• Improperly filled tube
• Hemolysis
• Clotted specimen
• Delay in transport
• Improper storage/transport temperature
• Patient on heparin > 1.0 IU/mL

Enzyme-linked immunosorbent assay (ELISA)

Negative