[Biophysics of the DNA molecule: a new trend].

Briefly discussed are experiments with single molecules, representing a novel trend in the biophysical study of DNA. The techniques of optical and magnetic tweezers whereby external force can be applied to individual DNA molecules were used to assess the structural transitions of the DNA double helix under such conditions. Discussed are the latest data on the dependence of the rate of complementary chain synthesis by DNA polymerase on the stretching of the template.