Measurement of the elastic energy of sharply bent ds DNA

We present measurements of the elastic energy of short (30 bp), sharply bent, ds DNA molecules. The measurements are obtained by two independent methods: one is based on the monomer-dimer equilibrium of an appropriate configuration where the elastic energy stored in the bent strands drives dimer formation; the other is based on melting curves analysis. We find that, for example, the elastic energy of a sharply bent 30 bp double stranded DNA molecule with a nick at the center does not exceed 10 kBT.