Hgb A1: 95–98%
Hgb A2: 2–3%
Hgb F: 0.8–2%; Newborn: 50–80%; > 6 mo old: 1–2%
Hgb C, S, or E: 0%
. Lavender-top tube.
■ Used to screen for abnormal hemoglobins.
■ Hemoglobin A, A2 and F are normal hemoglobins. Hgb F is the
predominant fetal hemoglobin.
■ Hgb S is the predominant hemoglobin found in people with
sickle cell disease.
■ Hgb C and Hgb E produce mild hemolytic anemia and
splenomegaly. They are considered relatively benign. Hgb E is
extremely common in Southeast Asia.
