A blood sample is needed.

There is no special preparation for this test.

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.

This test is most often used to check the levels of antibodies when certain cancers and other disorders are present or suspected.

A normal (negative) result means that the blood sample had normal types of immunoglobulins. The level of one immunoglobulin was not higher than any other.

An abnormal result may be due to:

• Amyloidosis (buildup of abnormal proteins in tissues and organs)
• Leukemia or Waldenström macroglobulinemia (types of white blood cell cancers)
• Lymphoma (cancer of the lymph tissue)
• Monoclonal gammopathy of unknown significance (MGUS)
• Multiple myeloma (a type of blood cancer)
• Other cancers
• Infection

There is little risk involved with having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight, but may include:

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

Serum immunofixation

Aoyagi K, Ashihara Y, Kasahara Y. Immunoassays and immunochemistry. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 45.

Updated by: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.