As the temperature of an alcohol-aqueous solution decreases, its dielectric constant increases. Therefore, in principle, at increasingly chilled temperatures, precipitation efficiency should diminish. Moreover, as the temperature decreases, the viscosity of the solution increases, which retards the movement of the nucleic acid aggregate, especially if the aggregate is small. In addition, since solubility decreases at lower temperatures, more salts will begin to co-precipitate with the nucleic acids at lower temperatures. Therefore, incubation at temperatures below 0°C is counter-productive and not recommended.