Manipulation of cells in open dishes is often incompatible withpreservation of sterility. A dish covered with an elastic orstretchable latex or plastic film allows manipulation of cellsthrough the film with preservation of sterility of the cultureand the integrity of the film. The latter forms a `microglove'for the instrument tip. The idea of manipulation through a thintransparent film is also applicable to general surgery, so thatthe surgeon's hand operates through a film and without a glove.