Definition of Protein electrophoresis - serum:

This test measures the types of protein in the fluid (serum) part of a blood sample.

See also:

• Immunoelectrophoresis - serum
• Immunofixation - serum
• Serum globulin electrophoresis

How the test is performed:

A blood sample is needed. For information on giving a blood sample from a vein, see venipuncture.

Electrophoresis is a laboratory technique. The blood serum (the liquid part of the blood without the cells) is placed on specially treated paper and exposed to an electric current. The proteins in the serum move on the paper to form bands that show the proportion of each protein fraction. A fraction may contain several different types of proteins.

Individual proteins, except albumin, are not usually measured. However, protein fractions or groups ARE measured. The levels of protein fractions can be estimated by measuring the total serum protein and then multiplying that by the relative percentage of each protein fraction.

Lipoprotein electrophoresis is a type of protein electrophoresis that determines the amount of proteins made up of protein and fat, called lipoproteins (such as LDL cholesterol).

How to prepare for the test:

You may be asked not to eat or drink for 12 hours before a lipoprotein electrophoresis test.

Your health care provider may ask you to stop taking drugs that could affect the test. Do not stop taking any medications without first talking to your health care provider.

Drugs that can affect the measurement of total 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:

Proteins are made from amino acids and are important components of all cells and tissues. There are many different kinds of proteins in the body with many different functions. Examples of proteins include enzymes, certain hormones, hemoglobin, low-density lipoprotein ("bad" cholesterol), and others.

Serum proteins are classified as albumin or globulins. Albumin is the protein of highest concentration in the serum. It carries many small molecules, but is also important for keeping fluid from leaking out from the blood vessels into the tissues.

Globulins are divided into alpha-1, alpha-2, beta, and gamma globulins. In general, alpha and gamma globulin protein levels increase when there is inflammation in the body.