Nearly instantaneous, cation-independent, high selectivity nucleic acid hybridization to DNA microarrays

Hybridization rate enhancement has been demonstrated for high molecular weight DNA target binding to a microarray. Microarrays were fabricated using biotin-modified oligonucleotides complexed with streptavidin (SA), which serves as an attachment to the underlying surface. It is shown that at low salt and pH 5, where SA develops a positive charge, duplex formation becomes at least 80-fold faster than seen under standard conditions, where SA is neutral or anionic. Duplex formation becomes independent of solution state cation concentration in the low pH state, under conditions where specificity remains high. The utility of such applied surface science is discussed.