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
thalassemia, may cause hemoglobin A levels to be low
and hemoglobin F levels to be high.
Hemoglobin F (fetal hemoglobin). This type is normally found in
fetuses 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
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