Which of the following hemoglobins migrates to the same position as Hgb S on agarose?

The correct answer is that Hgb DPunjab migrates to the same position as Hgb S on agarose gel electrophoresis due to its similar charge and structure. Hemoglobin S (Hgb S), which is associated with sickle cell disease, has a greater tendency to polymerize when deoxygenated, resulting in a distinctive characteristic during electrophoretic separation. Hemoglobin DPunjab, while being structurally different from Hgb S, possesses a similar net charge at the pH used in electrophoresis, allowing it to migrate to the same position.

Understanding the migration patterns of different hemoglobins is crucial in clinical settings for diagnosing various hemoglobinopathies. Hemoglobin E, Hgb C, and Hgb OArab have distinct characteristics and charges that result in different migration patterns when subjected to electrophoresis, hence they do not share the same position on the gel as Hgb S. This is important for accurate identification and diagnostic differentiation between these hemoglobin variants.