Method of preserving lyophilized microorganisms for transport, storage and recovery of viable microorganisms

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. The invention also provides a means for recovery of viable microbial cells by direct inoculation to solid or liquid culture media as recommended for use in performance or quality control testing of culture media, stains, identification kits, maintenance of stock cultures and in the evaluation of bacteriological procedures. Additionally, the device can be used to mimic clinical specimens in clinical or industrial proficiency testing surveys that test the ability of laboratory technologists to properly perform diagnostic procedures.