Diagnosis of sicklecell anemia

 Diagnosis of sicklecell anemia:-

1. Sickling test : This is a simple microscopic examination of blood smear

prepared by adding reducing agents such as sodium dithionite. Sickled

erythrocytes can be detected under the microscope.

2. Electrophoresis : When subjected to electrophoresis in alkaline medium (pH

8.6), sicklecell hemoglobin (HbS) moves slowly towards anode (positive

electrode) than does adult hemoglobin (HbA). The slow mobility of HbS is

due to less negative charge, caused by the absence of glutamate residues that

carry negative charge. In case of sicklecell trait, the fast moving HbA and

slow moving HbS are observed. The electrophoresis of hemoglobin obtained

from lysed erythrocytes can be routinely used for the diagnosis of sicklecell

anemia and sicklecell trait.

FIG. - Electrophoresis of hemoglobins at pH 8.6 (HbA–Normal adult

hemoglobin; HbS–Sickle cell hemoglobin).