Sign in →


Performing Laboratory

NorDx Laboratories

Useful For

Measuring heparin concentration in plasma

Method Name

Automated Colorimetric

Reference Values

Therapeutic range:

High Intensity:

0.3-0.7 IU/mL (drawn at least 6 hours after initiation and/or 6 hours after any rate change).

Days and Times Test Performed

Monday through Sunday

Report Available

1 Day

Available Stat

Specimen Type


Preferred Container

Light Blue Top Tube (Sodium Citrate) – Tube must be full at time of collection.

Specimen Collection and Handling

Collect specimen as follows:

1. Draw blood in light blue-top (3.2% sodium citrate) tube(s). Tube(s) must be full upon collection.

2. Separate plasma from cells as soon as possible within 4 hours of collection in a centrifuge at 2,500 rpm for 15 minutes or 3,000 rpm for 10 minutes.

3. Using a plastic transfer pipette (do not use a glass pipette) decant the plasma to a screw-capped, plastic (polypropylene) vial. Glass vials will not be accepted.

4. Spin the plasma again at 2,500 rpm for 15 minutes or 3,000 rpm for 10 minutes. Note: Double spinning the specimen ensures platelet poor plasma (<10,000 uL)

5. Divide the plasma into as many 0.5-1.0 mL aliquots as possible and cap the vial(s) tightly.

6. Place tubes upright and flash freeze specimen(s) immediately at ≤ – 20° C or below.

7. Send specimen(s) FROZEN on dry ice.

NOTE: TYPE OF HEPARIN USED IS REQUIRED ON REQUEST FORM FOR PROCESSING (i.e., unfractionated, Lovenox, Fragmin, or Tinzaparin)

Click here to view the Procedure for Collecting a Specimen from an A-line

Rejection Information

Underfilled (<90 %), clotted, high hematocrit (>55 %), or grossly hemolyzed specimen

Specimen Stability Information

Specimen Type: Plasma

Frozen: 1 Month

Room Temp: 4 Hours

Note: Whole blood that remains capped and unspun is stable for up to 4 hours when stored at room temperature (18 – 24°C). Frozen plasma is stable 2 weeks @ -20°C and 12 months @ -70°C. Blue top tubes for coag assays must not be refrigerated or placed on ice.

Add On Capable

Not Permitted

Advance Beneficiary Notice Requirements

No ABN Required

CPT Code Information

CPT Code

CPT Description

CPT Disclaimer

85520 Heparin Assay

LOINC Code Information


Performing Laboratory Location

NorDx Laboratories