An effective microbial preservation technology for the long-term storage of viable prokaryotic cells is described. The method combines an almost instantaneous drying step with minimal stress to the cells during drying to maximize survival on rehydration. This is achieved by contact of a microlitre aliquot of a bacterial suspension with a novel, pre-dried activated charcoal cloth based matrix contained within a re-sealable system that can then be stored. The simple methodology completely circumvents the requirement for further drying or preparation. Using this method, a standard laboratory Escherichia coli strain was successfully revived following 390 days storage at 4, 20 and 30 degrees C. Data obtained yielded approximately 20%, 6% and 0.1% viable organisms at the aforementioned temperatures, respectively, following initial inoculations of 1.1 x 10(8)/microl cells. While these figures represent a significant viability loss, there is sufficient recovery of microorganisms required for maintaining culture collections.