This invention pertains to solubility enhanced polymers and methods, kits and compositions which enhance the aqueous solubility of said polymers. One set of preferred methods, kits and compositions embody or utilize phosphorous containing synthons and are most useful for modulating the solubility of synthetic nucleic acids and synthetic nucleic acid analogs. A second set of preferred methods, kits and compositions are most useful for modulating the aqueous solubility of peptides, other polyamides and most preferably peptide nucleic add (PNA) polymers.