How Conventional Approaches to the Use of Polymer-Containing Composites in Molecular Diagnostics are Changing

— The known approaches to the isolation of biopolymers, in particular, nucleic acids (NAs), from biological samples are based on the binding of molecules to a sorbent (“positive selection”) with their subsequent elution using a suitable eluent. The review discusses the physicochemical processes underlying the development of methods for isolating NAs from biological samples. It has been shown that methods including the selective solid-phase extraction (i.e., reversible sorption) provide the possibility of miniaturization and automation of the respective processes. The review discusses the advantages of an alternative approach to NA isolation based on the use of special sorbents that bind proteins and other components of biological samples, while these sorbents exhibit sorption inertness towards NAs (“negative selection”). The approaches providing the creation of such composite polymer-containing sorbents, which are designed for the sample preparation during molecular diagnostics, as well as the methods of their effective use, are considered. It has been demonstrated that, due to an interdisciplinary approach using a complex of synthetic and analytical methods, it is possible to combine composite materials that are very different in structure and properties as a single object of study. Such nanostructured composites (based on porous silica, synthetic membranes, glass multicapillaries) contain fluoropolymers and polyanilines. The results of using such composites for selective isolation of NAs and/or proteins from biological samples are discussed. Alternative applications of such composites in molecular diagnostics, in particular, in mass spectrometry, are considered. Directions for expanding the field of application of polymer-containing composites due to simultaneous use of the sorption properties of the surface of composites obtained and the properties of sorbate molecules are outlined. It has been shown that both polymeric and low-molecular-weight modifiers of the same chemical nature are suitable for the technological preparation of such composites.