A thin-film culturing technique allowing rapid gas-liquid equilibration (6 sec) with no toxicity to mammalian cells

A method is described for inoculating mammalian cells onto the central area of glass petri dishes. The medium depth above the cells is only 100 microns for an added medium volume of 1 ml and increases linearly and rapidly with additional medium. The theoretical time constant for equilibration of the medium with the gas is related to the square of the medium depth. The experimental time constant was measured in two different ways for large and small medium depths, giving excellent agreement with the theoretical values. Although the time constant is only 6 sec for the case of 1 ml of added medium, there is no drying out of the medium or toxicity to the cells because of a large reservoir of medium in the meniscus at the periphery of the dish.