What it measures
Bence Jones protein is made of free light chains, small parts of antibodies, that pass from the blood into the urine. The test looks for them in a urine sample and, if they are found, names the type present (kappa or lambda).
Why people test it
- Measured when myeloma or a related condition of plasma cells is being looked into.
- Used alongside blood tests such as serum protein electrophoresis and free light chains.
- Monitored over time in people known to have one of these conditions.
Typical range
The result is reported as detected or not detected. If detected, the lab names the light chain type and may give the amount. Labs differ in their methods, and the report shows the lab's wording.
Finger-prick or vein?
This is not a blood test. It uses a urine sample, often the first urine of the morning; some clinics ask for a 24-hour collection instead.