Dual species strips contain both geobacillus stearothermophilus and bacillus atrophaeus spores allowing the strips to be used to test most sterilization processes including dry heat, steam, chemical vapor, and EO gas. During use, place the blue glassine envelope inside a product or product package. After processing, the BI is to be aseptically cultured in soybean casein digest medium, and incubated at the appropriate time and temperature. Soybean casein digest medium (culture media) is also available. Indicators come with a 2 year shelf-life when stored as directed. Each lot is shipped with a Certificate of Performance, which list lot specific information and any adherence to USP or ISO performance requirements.