[The state of a toroid-like DNA globule: the persistent macromolecule in a low-molecular solvent]

Dimensions of a toroidal globule appearing at the compactization of DNA macro-molecule in a poor low-molecular solvent are estimated. Diagram of DNA molecule state was analysed in variables: contour length-concentration of the precipitating agent. Possible existence of the tricritical point in the joint of the regions of coil, isotropic globular and liquid crystalline globular states was suggested.