Protein Electrophoresis Serum Test

Written by Krista O'Connell
Medically Reviewed by George Krucik, MD

Serum protein electrophoresis (SPEP) is a laboratory technique that is used to determine the levels of some types of proteins in a blood sample. Serum is the liquid part of your blood. There are a number of reasons why a doctor may order this test. One is to test for a cancer called multiple myeloma; another is to screen for multiple sclerosis, a chronic disease of the nervous system. SPEP is used to help diagnose or monitor a variety of different diseases or disorders that have abnormal proteins or protein levels. Electrophoresis is not usually used by itself to diagnose a disease. Instead, it is used along with other laboratory tests to provide more information to help with diagnosis.

One of the best ways to get a better sense of the test is to look at each word in the name:

Understanding Serum Protein Electrophoresis


Proteins are substances made of small chemicals called amino acids. They have a number of roles:

  • they provide structure to the body
  • they help transport nutrients
  • they help the body fight off disease

Too much or too little protein can cause problems. The five groups of proteins usually considered during an SPEP test are:

  • albumin: transports substances; plays a role in tissue growth and repair
  • alpha-1 globulins: the major alpha-1 globulin is called alpha-1-antitrypsin, which is produced by the lungs and liver, and increase with inflammatory diseases
  • alpha-2 globulins: a class of proteins that have many functions in the body, but are involved in inflammation
  • beta globulins: move substances; support immunity, and are increased in multiple myeloma and in conditions like high cholesterol and atherosclerosis
  • gamma globulins: support the immune system and are increased in multiple myeloma, as well as some autoimmune conditions like rheumatoid arthritis and systemic lupus erythematosis


Blood appears to be a single substance to the naked eye. But, it has several parts. Both types of blood cells (red and white) and platelets are solids. When these are removed, a liquid is left behind. This is serum.


Electrophoresis is a lab technique used to separate groups of proteins in blood serum. This allows them to be measured and analyzed individually. It involves exposing serum placed on a special type of paper to an electric current. This causes the different types of proteins to move and “group” together. The proteins create separate bands on the paper, which are then analyzed by the laboratory.

The Serum Protein Electrophoresis Test

No preparation is needed for the test. When you arrive, a healthcare professional will simply use a needle to take a blood sample. Some people experience slight pain when the needle is inserted. There may be some slight bruising afterwards.

The Lab Report: The Results Your Doctor is Hoping to See

The following table shows what most labs would consider normal results for SPEP testing. These values may vary slightly from facility to facility.

Type of Protein

Amount of Protein (grams/deciliter)



alpha-1 globulin


alpha-2 globulin


beta globulin


gamma globulin


What Abnormal Results for a Protein Electrophoresis Serum Test May Mean

The various proteins in the body perform different functions. This means that high or low levels of the five protein types examined during the test can point to different issues and illnesses. Keep in mind, however, that these are just clues. Further investigation will usually be needed to make a definitive diagnosis.


Test Result

Possible Condition(s)

Levels higher than normal


Levels lower than normal

Kidney or liver disease, a condition involving inflammation, poor nutrition

Alpha-1 Globulin

Test Result

Possible Condition(s)

Levels higher than normal

Disease leading to inflammation (condition may be chronic or acute)

Levels lower than normal

Liver disease, congenital emphysema (rare)

Alpha-2 Globulin

Test Result

Possible Condition(s)

Levels higher than normal

Kidney disease, disease leading to inflammation (condition may be chronic or acute)

Levels lower than normal

Liver disease, poor nutrition, breakdown of red blood cells

Beta Globulin

Test Result

Possible Condition(s)

Levels higher than normal

Anemia, multiple myeloma, high cholesterol

Levels lower than normal

Poor nutrition, liver cirrhosis

Gama Globulin

Test Result

Possible Condition(s)

Levels higher than normal

Rheumatoid arthritis, infection, liver cirrhosis, inflammatory disease, multiple myeloma, lymphoma

Levels lower than normal

Immune disorders and deficiencies

How Test Results May be Used to Decide Future Care

It’s not always obvious what high or low protein levels in the blood serum may mean. A doctor may use the results to make a diagnosis or decide on a course of treatment.

He or she may also order more tests. This will depend in part on the amount of testing that was done before the SPEP test. The test may also be performed again in the future. This can help the doctor decide how well therapies and medicines are working.

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