Serum or Plasma Free Light Chain Immunoassay (Quantitative)

Why This Test Is Done

Your healthcare provider may order this test if you have symptoms like fatigue, weight loss, or unexplained infections, or if you have a history of conditions such as multiple myeloma, lymphoma, or other blood disorders. It may also be used to monitor treatment progress or detect early signs of certain diseases.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it involves drawing blood from a vein. Avoid smoking or consuming alcohol for the same period if instructed.

How the Test Is Performed

A healthcare professional will draw blood from a vein in your arm using a small needle. You may feel a brief pinch, but the procedure is quick and typically painless. The blood sample is then sent to a lab for analysis using an immunoassay method to measure free light chains.

What the Results Mean

Results are compared to a baseline or reference range provided by your lab. Elevated levels may suggest conditions like multiple myeloma, lymphoma, or other immune-related disorders, while abnormal ratios (kappa/lambda) can help diagnose monoclonal gammopathies.