Isolation of nucleic acids on surfaces

New processes and equipment to isolate and purify nucleic acids on surfaces are provided. The invention focuses on processes which use surfaces, for example, porous membranes, on which the nucleic acids are immobilized in a simple manner from the sample containing the nucleic acids and can be released again by way of simple procedural steps, whereby the simple performance of the process according to the invention makes it possible to perform the processes specifically in a fully automatic manner. An additional aspect of the present invention focuses on binding the nucleic acids to an immobile phase, especially to a membrane, in such a way and manner, that they can be released without difficulty during an additional reaction stage from this phase and, if desired, can be used in other applications, such as restriction digestion, RT, PCR or RT-PCR, or in any of the suitable analyses or enzyme reactions mentioned in the disclosure. Special isolation devices are provided that can be used to carry out the processes according to the invention.