Delivering a payload across a plasma membrane of a cell includes providing a population of cells and contacting the population of cells with a volume of an aqueous solution. The aqueous solution includes the payload and alcohol content greater than 5 percent concentration. The volume of the aqueous solution may be a function of exposed surface area of the population of cells, or may be a function of a number of cells in the population of cells. Related compositions, apparatus, systems, techniques, and articles are also described.
