Figure 1. Sequences containing Affinity Plus show identical annealing properties to locked nucleic acid sequences from another manufacturer. The percentages of duplex melted base pairs are plotted as a function of temperature. The 15-mer sequence, GGTCCT+T+A+CTTGGTG, was synthesized with either Affinity Plus or other locked nucleic acid modifications incorporated at the +T, +A, and +C sites. These oligos were mixed with the complementary DNA strand (1 µM each strand) in 1 M Na+ buffer (pH 7). Melting curve analyses were performed as described in Owczarzy, et al . The plots of duplex melted base pairs were averaged from at least 7 heating and cooling melting curves. Melting temperature was measured to be 67.7 ± 0.3°C for the Affinity Plus oligo and 67.9 ± 0.3°C for the other locked nucleic acid oligo. Free energy of duplex hybridization at 37°C was determined to be -18.1 ± 0.9 kcal/mol for the Affinity Plus oligo and -18.7 ± 0.9 kcal/moI for the other locked nucleic acid oligo. These results demonstrate the identical annealing properties of both sources of locked nucleic acid sequences.