Abstract: Modified nucleotides and polynucleotides which are useful in hybridization assays for the detection of target genes are provided. The modified polynucleotides contain at least one boronic acid moiety which is attached to a nucleotide base in a position which does not interfere with the hydrogen bonding capabilities of that base during duplex formation. The modified polynucleotides are typically formed from naturally occurring nucleotides and one or more modified nucleotides.