Abstract: The invention relates to a method for preserving samples and disrupting cells which can be employed for the preparation of the extraction of nucleic acids from live cells, cell aggregates and tissue samples, and to a kit for carrying out the method. The method includes the introduction of live cells, cell aggregates or tissue samples whose nucleic acids are to be extracted into an excess of water-miscible and volatile organic liquid. The saturation of the sample with the organic liquid has an advantageous effect on the extraction of the nucleic acids, which is subsequently carried out in an aqueous medium. The mechanical cell disruption is facilitated by the virtually complete removal of the water from the cells. The biomembranes are dissolved in the organic liquid. tRNA and other RNA fractions with a low degree of polymerization, which are capable of permeating across the cell wall, can be extracted selectively without mechanical disruption.