The invention relates to methods for drawing-off liquid from individual droplets which are in a predefined arrangement on a flat substrate and have sedimented material enclosed in them. A mask of an absorbent material comprising a pattern of indentations or holes which corresponds at least partially to the regular arrangement of the individual droplets, or a stiff, rigid plate of an absorbent material is positioned above the flat substrate in such a way that the droplets come into contact with the absorbent material peripherally so that liquid is drawn off there-into. The invention also relates to a mask of an absorbent material with a substantially rectangular shape which has a predefined pattern of indentations or holes for the purpose of separating liquid and sedimented material enclosed therein.