Serum immunoelectrophoresis is a test that tells whether or not you have immunoglobulins in the blood. Immunoglobulins are proteins that make antibodies. The proteins can be abnormal. There are various types of immunoglobulins. If you do have these proteins, this test can also help identify what specific type they are.

Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic. An elastic band is placed around the upper arm to apply pressure and cause the vein to swell with blood.

A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the band is removed to restore circulation. 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, the area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. A bandage may be applied to the puncture site if there is any bleeding.

When the needle is inserted to draw blood, you may feel moderate pain, or only a prick or stinging sensation. Afterward, there may be some throbbing.

This test is performed to assess the clonality (monoclonal or polyclonal) of immunoglobulins.

No monoclonal antibodies are detected.

In some malignant disorders (that is, multiple myeloma, chronic lymphocytic leukemia) a single clone of lymphocytes produces one type of protein -- a monoclonal immunoglobulin. This is identifiable as monoclonal (all the same type) by immunoelectrophoresis. Some people have monoclonal immunoglobulins, but do not have a malignant disorder.

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

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

McPherson RA and Pincus MR. Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. Philadelphia, Pa: WB Saunders; 2007.

Hoffman R, Benz Jr. EJ, Shattil SJ, et al., eds. Hematology: Basic Principles and Practice. 4th ed. Philadelphia, Pa: Churchill Livingston; 2005.