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.
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.
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.
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.
- 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.
Increased gamma globulin proteins may indicate:
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)
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.