Sterdoc self-contained Steam Biological Indicator is designed for simulating sterilization ability of steam sterilizers. Living stearothermophilus spores are heat and steam resistant microorganisms. When a sterilizer is able to kill these microorganisms, it means that pathogen or non-pathogen microorganisms like bacteria, virus or fungi, will be destroyed.
Biological Indicators contain enough spore quantity to make sure that the sterilization process is successful. Each BI consist of a plastic heat resistant transparent vial, a spore contained paper at the bottom, a glass vial of culture media liquid, one paper protection filter and a blue cap to protect the content. Furthermore, the BI has a Type 1 Chemical Indicator label with EXP date, LOT number and spore quantity. The color of the Chemical Indicator label will change from Blue to Brown if it is exposed to the sterilizer.
Biological Indicators are used for routine control tests, implant surgeries and after any sterilizer calibration.
How to process the Biological Indicator?
Once sterilization cycle is finished, the Biological Indicator must be incubated by a standard incubator machine. Regular steam indicators need to be incubated for 24 hours in 57-60⁰C.
If any live spores remain, the color of liquid culture media will change from Purple to Yellow – which is a result of a chain reaction of enzymatic color change. Yellow color in the BI stands for that it has failed the sterilization cycle (positive test). The instruments that are related to this BI cycle (which is failed), is not allowed to be used. Also if BI results fail for the next cycles, sterilizer needs to be re-calibrated and checked by a BI indicator. In some conditions, the Biological Indicators are packed incorrectly and steam is not able to penetrate to expose the spores. Before calibrating the sterilizer, it is necessary that we use unpacked BI’s.