Transduction of MPG-EGFP is independent on caveolae but may share a pathway with transferrin. A. Jurkat cells were treated with 40 μg/ml MPG-EGFP for 1 hr. Cells were processed for flow cytometry after the acid wash. In Jurkat cells which lack caveolae, the transduction of MPG-EGFP still occurs. Confocal live image of MPG-EGFP-treated Jurkat cells is shown at 80X. B. Live confocal images showing partial co-localization of transferrin (red) and MPG-EGFP (green) in HeLa cells, generating a yellow fluorescence. Transferrin was added at 50 μg/ml for 30 min along with 40 μg/ml MPG-EGFP. Pre-treatment of amiloride (4 mM for 30 min) significantly reduced MPG-EGFP transduction while transferrin uptake proceeds.