Biological indicator for determining the efficacy of a sterilization process and methods of use

A method of determining the efficacy of a sterilization process, by means of a self-contained biological indicator, wherein said biological indicator comprises, in a single container, a set of microbial spores, at least one sensor molecule, and a culture medium,

• wherein the at least one sensor molecule being capable of yielding an optically detectable signal when the at least one sensor molecule is not in a inactivated state due to the sterilization process, the at least one sensor moleculre being further capable of yielding a different optically detectable signal when the at least one sensor molecule is in a inactivated state after the sterilization process, said difference being independent of a catalytic activity of the at least one sensor molecule and the culture medium being brought into contact with the set of microbial spores,
• wherein said culture medium being capable of inducing growth of any viable microbial life present after the sterilization process,
• wherein said culture medium comprising a colorimetric component being capable of undergoing an optically detectable color shift in the presence of microbial growth, and
• wherein the method comprises the steps of:
• a) placing the biological indicator along with a target material to be sterilized within a sterilizer;
• b) carrying out a sterilization process;
• c) placing the biological indicator in an incubator;
• d) screening the biological indicator for immediate detectable changes in fluorescence intensity, while incubating the biological indicator in the incubator;
• e) determining the efficacy of the sterilization process based on the screening carried out during step d);
• f) extending the incubation of the biological indicator obtained in step d);
• g) screening the incubated biological indicators obtained in step e) for an optically detectable color change;
• and
• h) determining the efficacy of the sterilization process, according to optically detectable changes obtained in step g).