Gel-filtration of Isotopically labelled Ferritin from HeLa Cells

Abstract

HELA human cancer cells have been shown to produce ferritin when grown in the presence of iron¹. HeLa ferritin is electrophoretically heterogeneous; its properties have been compared with those of ferritin isolated from other cells grown in vitro and from human and animal tissues². On DEAE chromatography of homogenates of HeLa cells grown in the presence of FeSO₄ (⁵⁹Fe), the distribution of the radioactivity was practically the same as the distribution of ultra-violet-absorbing components in the case of purified horse ferritin; the assignment of the activity to ferritin has been confirmed by paper electrophoresis³. The use of radio-iron in such experiments results in great sensitivity and specificity. We now report the behaviour of HeLa ferritin on gel-filtration.