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Serum Globulin Electrophoresis

Definition

Serum globulin electrophoresis is a laboratory test that looks at proteins called globulins in the blood.

See also:

Alternative Names

Globulin electrophoresis

How the test is performed

Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

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, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.

The blood sample is sent to a lab. The fluid part of blood (serum) is placed on specially treated paper and exposed to an electric current. The proteins move on the paper to form bands that show the amount of each protein fraction in relation to the other protein fractions.

How to prepare for the test

Fast for 4 hours before the test. The health care provider may advise you to stop taking drugs that can interfere with the test. Do NOT stop taking any medications without first telling your health care provider.

Drugs that can affect the measurement of serum proteins include chlorpromazine, corticosteroids, isoniazid, neomycin, phenacemide, salicylates, sulfonamides, and tolbutamide.

How the test will feel

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

Why the test is performed

This test is performed to look at globulin proteins in the blood. Identifying the types of globulins can help diagnose certain disorders.

Globulins are roughly divided into three groups: alpha, beta, and gamma globulins. Gamma globulines include various types of antibodies such as immunoglobulins (Ig) M, G, and A.

Certain diseases are associated with overproduction of immunoglobulins. For example, Waldenstrom's macroglobulinemia is a cancer of certain white blood cell that is associated with the overproduction IgM antibodies.

Normal Values

  • Serum globulin: 2.0 to 3.5 g/dL
  • IgM component: 75 to 300 mg/dL
  • IgG component: 650 to 1850 mg/dL
  • IgA component: 90 to 350 mg/dL

Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

What abnormal results mean

Increased gamma globulin proteins may indicate:

  • Acute infection
  • Chronic inflammatory disease (for example, rheumatoid arthritis and systemic lupus erythematosus)
  • Hyperimmunization
  • Multiple myeloma
  • Waldenstrom's macroglobulinemia

What the risks are

There is very little risk involved with having your blood taken. Veins and arteries vary in size from one patient 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 light-headed
  • Hematoma (blood accumulating under the skin)
  • Infection (a slight risk any time the skin is broken)

References

McPherson R. Specific proteins. In: McPherson RA, Pincus MR. Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. Philadelphia, Pa: Saunders; 2006:chap 19.

Tricot G. Multiple Myeloma. In: Hoffman R, Benz EJ, Shattil SS, et al, eds. Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2008:chap 87.

Review Date: 3/21/2010

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Information developed by A.D.A.M., Inc. regarding tests and test results may not directly correspond with information provided by UCSF Medical Center. Please discuss with your doctor any questions or concerns you may have.