Why is citrate agar used when identifying abnormal hemoglobins on cellulose acetate at pH 8.6?

Citrate agar is specifically chosen for identifying abnormal hemoglobins during electrophoresis on cellulose acetate at a pH of 8.6 because it enhances the separation of different types of hemoglobin based on their respective charges and mobility. At this alkaline pH, hemoglobin S (HbS) and hemoglobin D (HbD) exhibit distinct migration patterns due to their differing charges. This allows for better resolution and differentiation between abnormal hemoglobins, which is crucial for accurate diagnosis and understanding of hemoglobinopathies.

Using citrate agar not only aids in facilitating the separation process but also contributes to the stability and integrity of the hemoglobin molecules during the electrophoresis process, making it easier to identify them precisely based on their unique characteristics. The ability to effectively separate HbS from HbD is fundamental in clinical diagnostics, particularly in conditions such as sickle cell disease or other hemoglobin variants. Hence, its use in the electrophoresis process is integral for identifying and differentiating between these abnormal hemoglobin types.