Sterilisation Monitoring

Sterilisation and Biological Indicators

It is important that cleanroom personnel not only maintain the sterility of the clean environment but also test for the sterilisation process’s effectiveness. Biological indicators have largely been the industry standard for monitoring a sterilisation process as the highly resistant spores used (of the Bacillus or Geobacillus species) can definitively determine whether or not sterilisation has been effective by directly assessing the process’s lethality to microbes.  As the spores in Biological Indicator testing kits are stronger and more resistant than normal pathogens typically found in the lab or clean environment, inactivating BI spores is a quantifiable indicator other pathogens have been cleared successfully as well.

Biological indicators for sterility testing come in microbiological testing kit, which contains a live culture of inoculated spores ready for use.   These highly resistance spores provide a definable resistance to sterilisation procedures, and such procedures should only be considered successful once the desired inactivation of the spores has been achieved in accordance with the clean environment’s sterilisation monitoring programme.

Biological monitoring of the effectiveness of a sterility process should be inexpensive, easy to use, and provide definitive results as quickly as possible so that corrections can be made to sterilisation parameters.  This is why Biological Indicators are the current gold standard in providing an ideal monitoring solution for sterilisation.


How often should biological monitoring be carried out?

Sterilisation cyclers and procedures will be laid out in the cleanroom or clean environment operative, set by the company or institution invested in maintaining the clean space. Biological Indicator manufacturers recommend using BIs at least weekly to test the effectiveness of sterilisation processes.  A control group Biological Indicator (one that has not undergone sterilisation) should also be used and incubated in the same manner as the test Biological Indicator as should produce a positive control result.


Positive Biological Indicator spore tests

A positive result with Biological Indicators shows that a flaw exists within the current sterilisation process.  In this case, the first step is to review proper environment sterilisation procedure as outlined by the institute / employer / lab etc. and review whether all steps were followed.  Then, using the same steps in the previous BI test, test the environment again.  If the second result shows a negative, then it is possible human error lead to improper sterilisation protocol in the first instance. If the second test yields positive results again, then work within the cleanroom or clean environment will need to be suspended until such time as the sterilisation process can be reviewed and a new one implemented.


Enzyme Indicators to overtake Biological Indicators in Sterilisation Monitoring

Biological Indicators have long been accepted by the authorities as the gold standard in sterilisation monitoring as they provide definitive results attesting to the effectiveness of a sterilisation process.  BIs are depended upon in a variety of different industries, cleanrooms, and are crucial to aseptic manufacturing procedure, which is why when a test is positive so many industries feel the dread of halting work or production, waiting on the results of the biological indicator testing to come back.   This is where Enzyme Indicators are going to overtake their slower predecessors by providing reliable, instant testing results. The thermostable enzyme Adenylate Kinase used in Enzyme Indicators boasts high environmental tolerances and a reliable, quantifiable inactivation profile, and is testing to be super in sterilisation monitoring.  As the luciferin reaction Adenylate Kinase undergoes emits light, EIs produce quantifiable data on decontamination, unlike their Biological Indicator counterparts.  This enables EIs to give instant, reliable results in sterilisation monitoring.


Sterilisation monitoring and Protak Scientific

Protak Scientific was chosen the global exclusive commercialisation partner for Public Health England and is currently leading the way in Enzyme Indicator technology.  Protak Scientific are passionate about delivering this cheap, reliable and accurate means of testing and monitoring sterility to the scientific community, and as such thermostable Adenylate Kinase is currently in commercial trials.   With Enzyme Indicators there will be no more days of downtime for cleanroom environments as results are anxiously awaited, just reliable, instant results.