Serum protein electrophoresis
SPEP · protein electrophoresis · serum protein fractions · paraprotein test · M protein test
This blood test sorts proteins into groups and shows how much of each there is. It helps find inflammation and unusual proteins.
For long-lasting inflammation, high total protein or sed rate, bone pain, kidney and liver conditions, and when a blood disorder is suspected.
⏱ Duration: the blood draw usually takes 5 minutes; results usually come in a few days
Be sure to tell your doctor
How to prepare
- Food. Usually on an empty stomach: 8 to 12 hours without food. Water is fine. Check with the lab.
- Urine. Sometimes a urine protein test is ordered too. Ask if you need to collect urine.
- Medicines. Do not stop anything on your own. Tell your doctor what you take.
What to bring
- Your referral
- Past test results
- A urine container, if it was ordered
How it goes
- You sit down, and a band is tied above your elbow
- The skin is wiped with antiseptic
- Blood is taken from a vein into a tube
- The band is removed, and a cotton pad is pressed on the spot
What you'll feel
- A quick prick, like a pinch
- Sometimes slight dizziness. Tell the nurse, and they will help you lie down
Afterwards
- Press the cotton pad for 3 to 5 minutes
- Results usually come in a few days
- If an unusual protein is found, your doctor will order more tests. On its own, it is not a diagnosis
Common questions
My result says M spike. What is that?
Too much of one type of protein was found. There are many possible causes, often harmless. Your doctor will order more tests.
Why give a urine sample too?
Some unusual proteins show up better in urine. The urine test adds to the blood test.