FIG 6.

Receptor-mediated endocytosis of transferrin is inhibited at low temperatures. Monolayers of Vero and nTERT cells were incubated at the indicated temperatures for 10 min before the medium was replaced with medium containing Texas Red-conjugated transferrin (2.5 μγ/ml) at the same temperature for a further 30 min. Cells were fixed in 4% paraformaldehyde and nuclei stained with DAPI (blue). Images were acquired on a confocal Zeiss LSM510 META inverted laser-scanning microscope. Scale bar, 20 μm.