Light Blue Top Tube (Sodium Citrate) – (Use for Prothrombin Time or PT)


  1. Immediately prior to drawing the Light Blue Top Tube, clear the air out of the access tubing by partially filling a Red/Black Discard Tube and then discard. To accurately fill the Light Blue Top Tube with the correct amount of blood, fully seat and hold the Light Blue Top Tube against the back of the needle while filling. It is important not to let go of the Light Blue Top Tube while it is filling, as this may stop or impede the flow of blood. Allow the tube to fill until the vacuum is exhausted and blood flow ceases.
  2. The tube should fill between the draw volumes indicated on the tube. Tubes with less than the appropriate volume will be rejected as “Quantity Not Sufficient”.
  3. Allow the tube to fill until blood flow ceases to avoid dilution errors.
  4. Immediately after drawing, gently invert the tube 4 times to activate the anticoagulant and prevent clotting.
  5. Do not centrifuge.
  6. Use the bar code label with the patient’s name and ID to identify the specimen.
  7. Hold at room temperature. Do not refrigerate. Specimens can be collected and shipped Monday through Saturday, and must be received by the laboratory within 48 hours of collection.