What Are Biological Indicators?

Biological indicators were the foremost method of assessing the sterility of any medical or pharmaceutical environment through the use of some of the most resistant microorganism strains (eg. Bacillus or Geobacillus), rather than simply relying on meeting the requirements of both physical and chemical sterilization.  As the microorganisms used as biological indicators present in higher concentration and are more resistant than the common biological contaminants found in pharmaceutical or medical environments, tested environments found with inactive biological indicators can be of assured sterility.

However, biological indicators will likely be replaced by enzyme indicators. Unlike biological indicators, enzyme indicators uses thermostable Adenylate Kinase, an enzyme isolated from thermophilic Sulpholobus acidocaldarius bacteria, which are commonly found in thermal vents and hot springs.

Do biological indicators work

When biological indicators are used correctly with recommended frequency, they can be an accurate determinant of any given medical or pharmaceutical environment’s sterility.  As biological indicators are highly resistant microorganisms, you can be assured that any sterilization process that renders them inactive will have also killed off more common, weaker pathogens.

Biological indicator tests require a seven day incubation period before results can be determined, which is where enzyme indicators are overtaking the market with instant results of decontamination cycle performance.  Not only are the results of enzyme indicators instant, but enzyme indicators are manufactured to assure one-hundred percent accurate results to eliminate the lengthy and expensive false positive investigations that can often result with biological indicator tests.

How are biological indicators used

Biological indicators introduce highly resistant microorganisms to a given environment before sterilization, and then are measured afterwards to test the effectiveness of current sterilization processes.  Much like biological indicators, enzyme indicators achieve the same purpose, only with more accurate, quantifiable results delivered instantly and for a fraction of the costs associated with biological indicators.

Why are biological indicators important

Sterility is of the upmost importance when it comes to the health and safety of medical environments.  By using biological indicators to test the sterility of such environments regularly, environmental protection from more common, less resistant pathogens can be assured.  When it comes to making sure a medical environment is free of potentially harmful or disruptive pathogens, however, enzyme indicators outperform their biological counterparts by providing instant, quantifiable data that is 100% performance assured.

Enzyme indicators and the future of biological indicators

Adenylate kinase is an enzyme that is quickly revolutionizing measurement of decontaminate performance. tAK is an amazingly stable enzyme, boasts a high tolerance to decontamination processes, and has a predictable inactivation profile.  Unlike the seven day wait time of biological indicators, tAK enzyme indicators employ a luciferase / luciferin chemical reaction to provide instant quantifiable results.

This brand new technology comes from the isolation of the enzyme Adenylate Kinase from Sulpholobus acidoxaldarius, a thermophilic bacteria typically found in oceanic thermal vents and hot springs.  What makes tAK a superior monitor for decontamination processes is both its high environmental tolerance and it’s trackable inactivation profile.   After the luciferase reaction occurs the enzyme emits light, which can be correlated to tAK activity after decontamination.  A quantifiable, numerical value is reached by using a luminometer to measure light output from the indicators.

Enzyme indicators and Protak Scientific

Protak Scientific is on the pioneering edge of Enzyme Indicator technology, having been chosen as the global exclusive commercialization partner of the Public Health England for thermostable Adenylate Kinase usage.  Protak Scientific is currently within the trial phase for finalizing a commercial product using thermostable Adenylate Kinase, and is looking forward to bringing this cheaper, more reliable, and most importantly more accurate technology to the scientific community.

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