Provided are methods and compositions for preserving tissue samples containing nucleic acids, including DNA, at ambient temperatures and without the need for cold sampling or cold storage. After storage, the preserved DNA in the samples may then be processed and analyzed by known methods, e.g., PCR. The present invention provides in one aspect, a method for simple and rapid storage and/or processing of nucleic acids, such as DNA, from various sources, including but not limited to plants, tissues, bacterial cell lysates containing plasmids, etc. The present invention further comprises reagents and methods employing glycerol at alkaline pH to process biological samples and make DNA usable in PCR without further sample purification. Accordingly, the present invention provides in one aspect, a method for simple and rapid processing of nucleic acids, such as DNA, from various sources, including but not limited to plants, tissues, bacterial cell lysates containing plasmids, etc.
