Fluorescein-labeled antisense oligodeoxynucleotides (ODNs) corresponding to the promoters of the protooncogene c-myb (24-mer) and the oncogene c-myc (15-mer) were transported through the human skin in vitro by electroporation. Fluxes of 6.4 +/- 2.1 pM/cm2* hr and 11.5 +/- 3.5 pM/cm2* hr, respectively, were achieved during exponential pulsing [tau pulse = 1.1ms, transdermal voltage (Uskin) = 80V] every five seconds. The flux for Uskin < 70V was undetectable, rapidly increased at 80V, but plateaued at higher values. Fluorescence imaging demonstrated that transport of the ODNs is concentrated in localized transport regions (LTRs)1 approximately 30 microns in diameter.