Abstract
DNA solution is described by a one-dimensional Ising model with a long-range poly-spin interaction in an inhomogeneous 'magnetic field'. The model is used to calculate DNA thermodynamic properties, e.g. heat capacity and optical density. They exhibit oscillations which can be used to obtain important information about the DNA component sequence. This is demonstrated by an example of a particular DNA. The long-range interaction yields a phase transition. Its nature is shown to depend crucially on well defined properties of the DNA sequence.