Patient education: Serum protein electrophoresis and immunofixation (The Basics)

What is serum protein electrophoresis? — 

Serum protein electrophoresis, or "SPEP," is a test to measure the level of certain proteins in the blood. "Serum" is the liquid part of blood.

Certain health problems can cause the levels of different proteins to change, or abnormal proteins to form.

For SPEP, you give a sample of blood. Then, an electrical current is used on the sample to separate several different types of protein in the blood. This measures the amount of each of these protein types and shows patterns that can give your doctor information about your health.

What is immunofixation? — 

This is a test that can be used along with SPEP to learn more about the proteins in the blood.

If the SPEP pattern shows unexpectedly high levels of 1 type of protein, immunofixation can give doctors more information and help them figure out the cause. It can show if the high level is due to many copies of the same protein (called "monoclonal" proteins) or many different proteins (called "polyclonal" proteins). It can also tell the doctor more about the type of protein involved, and can sometimes find proteins that are missed by SPEP.

Another way of doing this is with a process called "mass spectrometry."

Why might I need these tests? — 

Your doctor might order these tests to:

●Check for certain types of cancer, including multiple myeloma, Waldenström macroglobulinemia, and AL amyloidosis

●Check for certain conditions that can affect the kidneys, liver, or other organs

●Learn more if you had other abnormal test results

●Help find the cause of frequent infections

●Monitor how treatment is working for certain types of cancer

How do I prepare for these tests? — 

You need to get a "blood draw." Your doctor or nurse will tell you where to go for this.

It might help to wear a short-sleeve shirt to your blood draw appointment. This makes it easier for the person drawing your blood to get to your arm.

What happens during a blood draw? — 

A needle is used to take a small amount of blood from your arm (figure 1). Collecting the blood only takes a few minutes. The blood is then tested in a lab.

Tell the person who takes your blood:

●If you take "blood thinner" medicines or have a bleeding problem – They will make sure your bleeding is under control before you leave.

●If you have a latex allergy – Some of the supplies used for blood draws might contain latex.

●If you have a preferred arm to use

Most of the time, getting blood taken does not cause problems. You might have a little soreness or bruising where the needle went in.

What do my results mean? — 

Your doctor or nurse will tell you when to expect your results, and will contact you with the results. Or if you use an online "patient portal," you might get an alert there when your results are ready.

If your SPEP or immunofixation test shows any abnormal results, your doctor or nurse will talk to you about what to do next. They might need to do more tests to figure out the cause.

If you do have a health problem, your doctor will work with you to come up with a treatment plan.

More on this topic

Patient education: Urine protein electrophoresis and immunofixation (The Basics)
Patient education: Multiple myeloma (The Basics)
Patient education: Waldenström macroglobulinemia (The Basics)
Patient education: AL amyloidosis (The Basics)

Patient education: Multiple myeloma symptoms, diagnosis, and staging (Beyond the Basics)
Patient education: Multiple myeloma treatment (Beyond the Basics)