Biological indicators provide the best assurance of sterility by challenging the sterilizer with quantifiable, highly resistant Bacillus stearothermophilus spores. The system includes rapid readout biological indicators, disposable test packs, auto-readers and log books. Biological indicators are used for load control monitoring which is the process by which a load is monitored and released based on the result of a biological indicator (BI) in a test pack.3MAttest 1292 Rapid Readout Biological Indicators for 121° Celsius (250° Fahrenheit) vacuum-assisted cyclesSelf-contained (BI) for 121° Celsius (250° Fahrenheit) gravity/132° Celsius (270° Fahrenheit) vacuum-assisted cycles consisting of a Bacillus stearothermophilus spore strip; sealed glass ampule with growth medium and dual indicator system; brown color-coded cap with holes for sterilant penetration and a hydrophobic filter as a bacterial barrier; and a chemical indicator on the label that changes from rose to brown when processed. After sterilization, the vial is "crushed" to join the growth media with the processed spore strip. The (BI) is incubated for three hours in the Attest 190 series auto-reader for a fluorescent reading. A red light indicates a positive result.3M Attest 190 Series Auto-readerDual function fluorescent reader/incubator for use with Attest rapid readout steam biological indicators. The incubator runs at 60° Celsius (140° Fahrenheit). The (BI) is crushed in the crusher well, transferred to the incubation wells for 3 hours, then placed in the reader well until a red or green light goes on. The auto-reader must be calibrated with a processed, non-incubated test vial every 12 hours or anytime the calibration light comes on. The auto-reader UV lamp and starter must be changed every 6 months for the test results to be valid. In addition, a positive control (unprocessed BI) from the same lot and manufacturing date must be incubated daily and each time the auto-reader is calibrated.