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Bence-Jones protein - quantitative

This test measures the level of abnormal proteins called Bence-Jones proteins in the urine.

How the Test is Performed

A clean-catch urine sample is needed. The clean-catch method is used to prevent germs from the penis or vagina from getting into a urine sample. To collect your urine, the health care provider may give you a special clean-catch kit that contains a cleansing solution and sterile wipes. Follow instructions exactly so that the results are accurate.

How the Test will Feel

The test involves only normal urination, and there is no discomfort.

Why the Test is Performed

Bence-Jones proteins are a part of regular antibodies called light chains. These proteins are not normally in urine. Sometimes, when your body makes too many antibodies, the level of light chains also rises. Bence-Jones proteins are small enough to be filtered out by the kidneys. Then they spill over into the urine.

Your doctor may order this test:

  • To diagnose health conditions that lead to protein in the urine
  • If you have a lot of protein in your urine
  • If you have signs of multiple myeloma

Urine immunofixation is a better test for detecting Bence-Jones proteins.

Normal Results

A normal result means no Bence-Jones proteins are found in your urine.

What Abnormal Results Mean

Bence-Jones proteins are rarely found in urine. If they are, it is usually associated with multiple myeloma.

An abnormal result may also be due to:

Alternative Names

Immunoglobulin light chains - urine; Urine Bence-Jones protein


McPherson RA, Ben-Ezra J. Basic examination of urine. In: McPherson RA, Pincus MR, eds.Henry's Clinical Diagnosis and Management by Laboratory Methods

Update Date 5/29/2014

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