HEK 293/RFP cells are derived from the human immortalized embryonic kidney cell line HEK 293 by stably integration of a constitutive RFP stably expression construct. HEK 293 cells have been widely used in cell biology research because of their reliable growth and propensity for transfection. HEK 293/RFP cells stably express RFP, can be used for in vitro assays and in vivo imaging.