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 . before high - molecular - weight nucleic acids are extracted , the cells , cell aggregates or tissue samples are disrupted in the organic liquid with the aid of mechanical pulses . since the nucleases are inactive in the dehydrated organic liquid , the biological samples or the homogenates prepared therefrom can be stored at room temperature in the organic liquid as long as desired . after incubation in the largely anhydrous organic liquid , the sample &# 39 ; s nucleases are largely denatured . an advantageous kit according to the invention contains a mixed organic / aqueous phase with denaturing properties and , for each sample , a shaped body for dehydration which is adapted to suit the size of the preservation container , and a mixture , adapted to suit the size of the preservation container , of a few large and many small disruption bodies for the disruption in the nonaqueous medium . a considerable advantage of the invention is the fact that cooling and powerful mechanical pulses when disrupting the cells and during the extraction may be dispensed with , and that dna extraction and cell disruption can be carried out at different times .