Method for testing a sterilization packaging unit

A method of testing a sterilization packaging unit provided for the sterilization of objects with regard to the efficacy of the sterilization packaging unit in preventing microbial recontamination of the sterilized objects after they have been sterilized, said method comprising:

• inserting within said packaging unit a test unit, permeable to microbes, said test unit comprising a dry matrix adapted to support a complete nutrient medium and a sealed receptacle containing a liquid, said receptacle being operatively associated with said dry matrix;
• sterilizing said packaging unit;
• storing said packaging unit for a time period under ambient conditions;
• opening said receptacle without opening the packaging unit and thereby allowing said liquid to contact said matrix, the combination of said liquid and said matrix providing said complete nutrient medium capable of supporting microbial reproduction on said matrix;
• subjecting said packaging unit to conditions favorable for cultivation of microbes present on said matrix;
• and
• observing microbes which have multiplied on said matrix.