Encapsulated biological indicator

Reference microorganisms are sealed into an interior cavity of a microporous membrane (14, 20). In one embodiment, the reference microbes are inoculated on a element (12) which is sealed in a microporous envelope (14) (FIG. 1). In another embodiment, the reference microbes (22) are loaded into an interior bore or cavity of a microporous plastic tube or envelope (20) (FIG. 3). The microporous membrane and the reference microbes, such as spores, are immersed concurrently with items to be microbially decontaminated separately into an anti-microbial fluid. The microporous membrane is constructed of a material which is sufficiently resistant to temperature, water, strong oxidants, and other anti-microbial agents or processes used for microbial decontamination or sterilization that it retains its integrity during the immersion in any common steam, gas, or liquid microbial decontamination or sterilization fluid or system. The micropores are sufficiently small that the reference microbes are entrapped, yet sufficiently open that anti-microbial steam, gas, or liquid are passed into the interior for direct contact with the reference microbes. After the microbial decontamination process, the microporous membrane and the contained reference microbes are immersed in a culture medium (40) and monitored to determine whether any of the reference microbes remain alive and commence growing.