What is hemoglobin electrophoresis?
Hemoglobin electrophoresis (pronounced he-ma-glow-bin elek-tro-fo-re-sus) is one process that healthcare providers use to analyze hemoglobin in your red blood cells.
Hemoglobin is a protein in your red blood cells that helps cells carry oxygen throughout your body. Sometimes, the gene controlling your hemoglobin changes or mutates, turning healthy red blood cells into damaged cells. These damaged cells can break down and cause anemia and other blood disorders like sickle cell anemia or thalassemias.
Hemoglobin electrophoresis helps healthcare providers diagnose those conditions. This test is also one of several tests that screen newborn babies for signs of sickle cell anemia and other rare but serious illnesses.
What’s the difference between a hemoglobin test and hemoglobin electrophoresis?
A hemoglobin test measures the amount of hemoglobin in your red blood cells. Hemoglobin electrophoresis analyzes the different types of hemoglobin in your red blood cells.
What are the different hemoglobin types?
Healthcare providers typically test for the four common hemoglobin types:
- Hemoglobin Types A11 and A2 (HgbA1 and A2): Hemoglobin A11 accounts for most of the hemoglobin in your normal red blood cells. Hemoglobin A2 accounts for about 2% to 3 % of your total hemoglobin.
- Hemoglobin Type F (HgbF): Normally, this hemoglobin type accounts for the largest part of red blood cells in fetuses, babies and children up to age 3. A high type F hemoglobin level in adults is considered an abnormal hemoglobin level.
- Hemoglobin Type S (HgbS): This hemoglobin type is a symptom of sickle cell anemia. Sickle cell anemia is an example of sickle cell disease. Sickle cell anemia is a serious illness that most commonly affects people who are Black.
- Hemoglobin C (HgbC): This hemoglobin type is linked to hemolytic anemia that develops when your red blood cells are destroyed more easily than normal red blood cells or have a shorter life span than normal red blood cells. Like sickle cell anemia, hemoglobin C most commonly affects people who are Black.
How does the test work?
This test is based on blood samples. Typically, healthcare providers obtain blood samples by drawing blood from a vein in your arm or hand. They may use finger stick devices or heel sticks to get blood from your child or newborn baby. Here is information about ways providers obtain blood samples.
- Venous blood draw: This is a medical term for a blood test done by drawing blood from one of your veins. To do this test, your healthcare provider swabs your skin with alcohol. Then, they place an elastic band around your upper arm and ask you to make a fist. This helps your blood flow more easily. You may feel some mild pain or discomfort when your healthcare provider inserts the needle.
Your provider collects your blood in a small vial or vials and sends them to a lab for analysis. Once they collect your sample, your healthcare provider puts a bandage on the site where the needle was inserted. That area may be bruised or swollen for a few days after your test.
- Finger stick: In this test, your healthcare provider pricks your fingertip to get a tiny sample of your blood. They store the sample on a specially designed test strip or vial. Sometimes, they use finger stick devices that simultaneously collect and store blood samples. Your child’s healthcare provider may use a finger stick test to get a sample of your child’s blood.
- Heel stick: This test is part of newborn babies’ health screenings. Healthcare providers usually do this test within 48 hours after your baby is born. The test involves pricking your baby’s heel with a needle to obtain a few drops of blood. You can hold your baby during the test. Healthcare providers place your baby’s blood sample on a strip of paper. Newborn screenings check for signs of rare but potentially troubling conditions. In this case, they’re checking for hemoglobin variants that may be a sign your baby has sickle cell anemia.
How do healthcare providers analyze blood samples taken for hemoglobin electrophoresis?
Hemoglobin electrophoresis uses electrical charges to separate hemoglobin types so healthcare providers can compare the level of each type with normal levels. The major hemoglobin types have different electrical charges. Here’s the typical test procedure:
- Healthcare providers place dissolved red blood cells from the sample on a cellulose strip.
- Then, they put the strip with the sample into a machine called an electrophoresis chamber. The chamber is a machine that passes electrical currents through the sample.
- Hemoglobin types react to the electric current, moving away from each other. Eventually the hemoglobin types appear as different-colored bands.
- Healthcare providers compare the test results with results from a normal hemoglobin sample.
- Hemoglobin type levels that are too high or too low may be signs of a blood disorder. For example, if your hemoglobin Type S looks different from a normal Type S, it could mean you have sickle cell anemia.
What is the difference between isoelectric focusing and electrophoresis?
Isoelectric focusing (IEF) is another technique for identifying abnormal hemoglobin. IEF and electrophoresis both use electric currents to separate hemoglobin types.
Results and Follow-Up
How long does it take to get hemoglobin electrophoresis results?
Processing the test may take about an hour, but it may be a few days before your healthcare provider receives and evaluates the test results.
What do my results mean?
There are ranges for each hemoglobin type. For example, if your hemoglobin Type F level is higher than normal, it could be a sign you have a form of thalassemia. But knowing test result numbers is just one part of any diagnosis. Your healthcare provider is your best resource for understanding your specific results.
My test results show some of my hemoglobin type levels are abnormal. When should I call my healthcare provider?
If you had a hemoglobin electrophoresis test because you had certain symptoms, you should call your healthcare provider to review your results.
A note from Cleveland Clinic
A hemoglobin electrophoresis test gives healthcare providers a snapshot of hemoglobin types. Hemoglobin type levels are a way of evaluating hemoglobin, a protein in your red blood cells. An abnormal change in your hemoglobin type levels may be a sign you have a medical condition. If your test results show you or your child may have a serious illness, it’s easy to focus on the snapshot. It can be harder to step back and look at the big picture, particularly if the big picture focuses on the health and wellbeing of your child or your newborn baby. If you receive test results that make you feel anxious, your healthcare provider can provide more information. Understanding how a snapshot fits into your big picture may help.
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