Oparin outlined a way he thought that basic organic chemicals might have formed into microscopic localized systems, from which primitive living things could have developed. He cited work done by de Jong and Sidney W. Fox on coacervates and research by others, including himself, into organic chemicals which, in solution, might spontaneously form droplets and layers. Oparin suggested that different types of coacervates could have formed in the Earth's primordial ocean and been subject to a selection process that led, eventually, to life.

While Oparin himself was unable to conduct experiments to test any of these ideas, later researchers tried. In 1953, Stanley Miller attempted an experiment to investigate whether chemical self-organization could have been possible on pre-historic Earth. The Miller–Urey experiment introduced heat (to provide reflux) and electrical energy (sparks, to simulate lightning) into a mixture of several simple components that would be present in a reducing atmosphere. Within a fairly short period of time a variety of familiar organic compounds, such as amino acids, were synthesised. The compounds that formed were somewhat more complex than the molecules present at the beginning of the experiment.