Abstract: A method of preserving microbial cells is provided, comprising dispensing microbial cells into preservation medium to produce a microbial cell suspension, impregnating a swab with a predetermined amount of the microbial cell suspension, and desiccating the impregnated swab. In one embodiment, the swab comprises a first end and a second end, wherein the second end comprises a network of fibers. In another embodiment, the method further comprises the steps of attaching the first end of the desiccated swab to a cap, inserting the desiccated swab into a tubular container, and sealing the tubular container with the cap.

Abstract: Incorporation of a microbial cell suspension throughout a fibrous network provides a physical environment that allows greater removal of water during lyophilization or desiccation thereby yielding a device with improved stability and recovery of viable microbial cells. Strands of appropriate fibers in a tightly knit network absorb aqueous cell suspensions by a capillary effect rather than absorption. When vapor pressure is decreased by vacuum during lyophilization or by air moved during desiccation, the surface tension is affected at the fiber/water interface, which results in increased water removal, by a “reverse capillary” effect. Thus bound and free water removal is increased. Therefore, incorporation of the use of a network of fibers in conjunction with a preservation matrix containing sensitive microbial cells provides a means of producing a preserved product with increased stability at both extreme and routine storage temperatures and greater efficacy for the end user.