Protein electrophoresis - serum
Key points
- This test roughly quantitates the various protein fractions in the serum portion of a blood sample.
- Blood is drawn from a vein, usually on the inside of the elbow or the back of the hand.
- The health care provider may advise you to discontinue drugs that could interfere with the test.
- The preparation you can provide for this test depends on your child's age and previous experience.
Definition
This test roughly quantitates the various protein fractions in the serum portion of a blood sample. See also Immunoelectrophoresis - serum; Immunofixation - serum; Serum globulin electrophoresis.
How the test is performed
Blood is drawn from a vein, usually on the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and an elastic band is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the band to swell with blood.
A needle is inserted into the vein, and the blood is collected in an airtight 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.
For an infant or young child, 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. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.
Electrophoresis is a laboratory technique. The blood serum is placed on specially treated paper and exposed to an electric current. The various proteins migrate (move on the paper) to form bands that indicate the relative proportion of each protein fraction.
Individual proteins, with the exception of albumin, are not usually measured. However, protein fractions or groups ARE measured. The levels of protein fractions can be roughly measured by measuring the total serum protein and multiplying by the relative percentage of each component protein fraction.
Lipoprotein electrophoresis is a type of protein electrophoresis that is focused on determining the amount of lipoproteins (materials such as LDL cholesterol).
How to prepare for the test
The health care provider may advise you to discontinue drugs that could interfere with the test. DO NOT discontinue any medication without discussing with your health care provider.
You may be advised to fast for 4 hours before a lipoprotein electrophoresis test.
For infants and children:
The preparation you can provide for this test depends on your child's age and previous experience. For general information regarding how you can prepare your child, see the following topics:
Written and revised by
David Cohen, M.D.
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