A series of random and alternating polyampholytes as well as polyampholyte "soaps" will be synthesized by free radical polymerisation from commercially available monomers. Electrochemical, hydrodynamic and conformational characteristics of polyampholytes in aqueous and aqueous-salt solution will be determined by modern technique. Amphoteric macromolecules will be modified by ionic surfactants and mixed micelles in order to tune the specific affinity of polyampholytes with respect to biomolecules and to realize the mechanism of "molecular recognition". Labelling of polyampholyte molecules by fluorescent tags will be performed to develop the fluorescence assay for polyampholyte-protein complexation. The main attention will be paid to interaction of polyampholytes with selected proteins and characterization of polyampholyte-protein complexes. Optimal conditions and appropriate polyampholytes will be selected to separate and purify the target biomolecules from their mixture. Several approaches to recycle polyampholytes will be developed.