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5'-nucleotidase (5'-NT) is a protein produced by the liver. A test can be done to measure the amount of this protein in your blood.

How the Test is Performed

Blood is drawn from a vein. Most of the time, a vein on the inside of the elbow or the back of the hand is used. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.

How to Prepare for the Test

Your provider may tell you to stop taking some medicines that could interfere with the test. Drugs that may affect results include:

  • Acetaminophen (Tylenol)
  • Halothane
  • Isoniazid
  • Methyldopa
  • Nitrofurantoin

How the Test Will Feel

You may feel slight pain or a sting when the needle is inserted. Afterward, there may be some throbbing.

Why the Test is Performed

Your doctor may order this test if you have signs of a liver problem. It is used mostly to tell if the high protein level is due to liver damage or skeletal muscle damage.

Normal Results

The normal value is 2 to 17 units per liter.

Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.

What Abnormal Results Mean

Greater than normal levels may indicate:

  • Cholestasis (when bile, which is made by the liver to help digest fats, is blocked from flowing out of the liver
  • Destruction of liver cells
  • Hepatitis (liver inflammation)
  • Liver ischemia (loss of blood and oxygen to the liver)
  • Liver tumor
  • Use of a liver-damaging drug


Slight from having blood drawn may include:

  • Excessive bleeding
  • Fainting or feeling light-headed
  • Hematoma (blood accumulating under the skin)
  • Infection (a slight risk any time the skin is broken)
  • Bruising

Alternative Names




Pratt DS. Liver chemistry and function tests. In: Feldman M, Friedman LS, Brandt LJ, eds.Sleisenger & Fordtran's Gastrointestinal and Liver Disease

Update Date 2/18/2015

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