Analysis of the stable clone. (A) Immunoprecipitation experiments on untrasfected (HeLa) and ΔH1 homogenate cells. The cells were metabolically labeled as described in “Materials and methods,” and 4 × 106 cpm of the cytosolic lysates were precipitated with saturating amounts of anti–H-ferritin antibody (αH). The precipitates were analyzed on 12% SDS-PAGE and exposed to autoradiography. Representative of 2 independent experiments with similar results. (B) Cellular extracts of untrasfected cells and ΔH1 clone were separated on 12% SDS-PAGE and blotted with an anti-TfR1 antibody. Representative of 2 independent experiments with similar results. (C) Analysis of the cells' vitality by MTT assay after growth in the presence or absence of 1 mM ferric ammonium citrate (+/-FAC) for 18 hours. (D) Cell mortality was monitored by trypan blue exclusion method after growing the cells without or with 0.1 mM DFO for 2 days. The data are expressed as percentage of the unstained cells to the number of cells counted. Data of panel C and D are means and SD of 3 independent experiments in octaplicate and triplicate, respectively.
