Optimize your sterilization processes with the help of bioindicator verification. Sterilization processes are crucial to ensure that medical devices, among other things, are free of viable microorganisms.


Bioindicators are an indispensable tool for monitoring and validating these processes.

Bioindicators, also known as sterilization indicators, are specially developed test systems that contain viable microorganisms. They are used in sterilization processes to ensure that the sterilization technique used was effective and that all microorganisms have been killed. Bioindicators are particularly useful in steam sterilization and gas sterilization processes.

The use of bioindicators requires compliance with specific requirements and standards to ensure the reliability and accuracy of the test results:

  • Viability of the microorganisms:
    The bioindicators must contain viable microorganisms that are highly resistant to the sterilization process used. Common microorganisms include Geo bacillus stearothermophilus for steam sterilization and Bacillus atrophaeus for ethylene oxide sterilization.
  • Accuracy:
    Sterilization processes can be examined in detail with the help of bioindicators. This requires a reliable quantitative or qualitative assessment of the survival of microorganisms.
  • Reproducibility:
    The production of bioindicators must be subject to strict quality controls in order to ensure consistent validity with regard to population density and D-value. The production and handling of the bioindicators should be carried out in accordance with strict GMP (Good Manufacturing Practices) guidelines.

The use of bioindicators in sterilization processes is subject to various standards and guidelines, including

  • ISO 11138 is the international standard that specifies requirements for bioindicators and their use in sterilization processes. It contains specific requirements for the production, validation and performance evaluation of bioindicators.
  • The United States Pharmacopeia (USP) chapter <55> deals with bioindicators and their use in pharmaceutical sterilization processes. It specifies requirements for bioindicators for steam sterilization, gas sterilization and other methods.

Bioindicators are indispensable instruments in the validation of sterilization processes. Their use makes it possible to ensure the effectiveness of sterilization techniques and to guarantee patient safety in medicine and reliability in other critical applications. Compliance with the applicable standards and requirements is crucial to achieve accurate and reliable results and to ensure that the sterility of the products is guaranteed.


  • ISO 11138: Biological indicators for ethylene oxide sterilization processes
  • USP <55>: Biological Indicators for Sterilization
  • Microbiological in-process controls
  • Quantitative evaluation

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