Medical Genetics In 1949, using an exquisitely sensitive new technique called electrophoresis that separated molecules by their electric charge, they found their answer: sickle-cell hemoglobin carried more positive electric charges on its surfaceMedical Genetics In 1949, using an exquisitely sensitive new technique called electrophoresis that separated molecules by their electric charge, they found their answer: sickle-cell hemoglobin carried more positive electric charges on its surface