A hemoglobin electrophoresis test is a blood test done to check the different types of hemoglobin in the blood. Hemoglobin is the substance in red blood cells that carries oxygen.
The most common types of normal hemoglobin are:
- Hemoglobin A. This is the most common type of hemoglobin found normally in adults. Some diseases, such as severe forms of thalassaemia, may cause hemoglobin A levels to be low and hemoglobin F levels to be high.
- Hemoglobin F (fetal hemoglobin). This type is normally found infetuses and newborn babies. Hemoglobin F is replaced by hemoglobin A (adult hemoglobin) shortly after birth; only very small amounts of hemoglobin F are made after birth. Some diseases, such as sickle cell disease, aplastic anemia, and leukemia, have abnormal types of hemoglobin and higher amounts of hemoglobin F.
- Hemoglobin A2. This is a normal type of hemoglobin found in small amounts in adults.
There are more than 350 types of abnormal hemoglobin.1 The most common are:
- Hemoglobin S. This type of hemoglobin is present in sickle cell disease.
- Hemoglobin C. This type of hemoglobin does not carry oxygen well.
- Hemoglobin E. This type of hemoglobin is found in people of Southeast Asian descent.
- Hemoglobin D. This type of hemoglobin is present in some sickle cell disorders.
Hemoglobin S and hemoglobin C are the most common types of abnormal hemoglobin that may be found by an electrophoresis test.
Electrophoresis uses an electrical current to separate normal and abnormal types of hemoglobin in the blood. Hemoglobin types have different electrical charges and move at different speeds. The amount of each hemoglobin type in the current is measured.
An abnormal amount of normal hemoglobin or an abnormal type of hemoglobin in the blood may mean that a disease is present. Abnormal hemoglobin types may be present without any other symptoms, may cause mild diseases that do not have symptoms, or cause diseases that can be life-threatening. For example, hemoglobin S is found in sickle cell disease, which is a serious abnormality of the blood and causes serious problems.
Why It Is Done
Hemoglobin electrophoresis is done to:
- Find each type of hemoglobin in the blood. This can be used to diagnose certain types of anemia (such as thalassemia).
- Check treatment for diseases that have abnormal types of hemoglobin in the blood.
- Help couples find out how likely they are to have a child with certain forms of anemia that can be passed from a parent to a child (inherited).
How To Prepare
Tell your doctor if you are getting iron therapy for iron deficiency anemia.
How It Is Done
The health professional drawing blood will:
- Wrap an elastic band around your upper arm to stop the flow of blood. This makes the veins below the band larger so it is easier to put a needle into the vein.
- Clean the needle site with alcohol.
- Put the needle into the vein. More than one needle stick may be needed.
- Attach a tube to the needle to fill it with blood.
- Remove the band from your arm when enough blood is collected.
- Put a gauze pad or cotton ball over the needle site as the needle is removed.
- Put pressure on the site and then put on a bandage.
How It Feels
The blood sample is taken from a vein in your arm. An elastic band is wrapped around your upper arm. It may feel tight. You may feel nothing at all from the needle, or you may feel a quick sting or pinch.
There is very little chance of a problem from having a blood sample taken from a vein.
- You may get a small bruise at the site. You can lower the chance of bruising by keeping pressure on the site for several minutes.
- In rare cases, the vein may become swollen after the blood sample is taken. This problem is called phlebitis. A warm compress can be used several times a day to treat this.
- Ongoing bleeding can be a problem for people with bleeding disorders. Aspirin, warfarin (Coumadin), and other blood-thinning medicines can make bleeding more likely. If you have bleeding or clotting problems, or if you take blood-thinning medicine, tell your doctor before your blood sample is taken.