Serum Free Light Chain Immunoassay (kappa and lambda)

Why This Test Is Done

Your healthcare provider may order this test to investigate symptoms like fatigue, weight loss, or unexplained infections. It’s also used to monitor conditions such as multiple myeloma, lymphoma, or other plasma cell disorders. Free light chains can be elevated when plasma cells produce too many of these fragments, which may indicate an underlying issue.

How the Test Works

Blood is drawn from a vein, typically in your arm. The sample is then sent to a lab where it’s analyzed using an immunoassay method to detect and measure the kappa and lambda light chains separately. This helps determine if levels are abnormal.

Sample Collection and Preparation

The test requires a simple blood draw. You may feel slight discomfort, but it usually takes a few minutes. Your provider will explain the process and ensure you’re comfortable. Avoid eating or drinking for a short time before the test if instructed.

What to Expect After the Test

After the blood draw, you can return to your normal activities immediately. You may experience mild bruising or soreness at the site, but this typically resolves quickly. Follow any specific instructions your provider gives you for post-test care.