Berlin has undertaken research on a broad range of areas in both physical and theoretical chemistry, involving stochastic dynamics of complex systems, chemical kinetics and transport of active species in condensed phase and in biological molecules, physical chemistry of liquids and solids, theoretical biophysics and physical aspects of prebiotic evolution, physical methods for the initiation of chemical reactions, in particular cryochemistry, radiation chemistry, photo, and high pressure chemistry. His research covers a vast range of fields, such as the theory of excess electrons in non-polar liquids and liquid noble gases, charge transfer under extreme conditions, chemical processes coupled to structural rearrangements of molecular environment, dispersive kinetics, the effects of correlated fluctuations in chemical and biological properties, the role of static and dynamic disorder in the mechanism of chemical processes in condensed media. Later works are focused on mechanism and kinetics of charge transfer and transport in DNA, culminated in a series of studies of various DNA constructs as building blocks of molecular circuitry. Berlin has published over 170 papers in scientific journals.