Fluorous-tagged oligonucleotide reagents and an oligonucleotide purification methodology making use thereof, the method comprising: Synthesizing oligonucleotides using oligonucleotide reagents each bearing at least one fluorous group to yield a mixture of synthesis products and reagents, the mixture including at least one target synthesized oligonucleotide bearing at least one fluorous group; passing the mixture through a separation medium having an affinity for the at least one fluorous group so that the target synthesized oligonucleotide bearing at least one fluorous group is adsorbed by the separation medium; washing the separation medium with at least a first solvent to selectively dissociate therefrom substantially all synthesis products and reagents of the heterogenous mixture other than the at least one target synthesized oligonucleotide bearing at least one fluorous group; and subsequently dissociating the at least one synthesized oligonucleotide from the separation medium, with or without the fluorous group.