The Evolution of Biological Indicator Systems

The rapid-read fluorescence technology within the STERRAD VELOCITY™ Biological Indicator/Process Challenge Device improves the speed and sophistication of readouts compared to visual techniques, whilst providing consistent, real-time audit records.

Ten years ago, biological indicators (BIs) commonly utilised visual readout methods to determine if the sterilization cycle successfully inactivated microorganisms. These BIs, now outdated, are slow indicators of potential sterilization failures, requiring one to seven days for growth readout results.

With the recent introduction of a fluorescence readout, the time to read for BIs has drastically improved. To date, the STERRAD VELOCITY™ System* has the fastest time to result, with a 15-minute** readout.

Rapid Readout Technology – 15 Minutes** to Results

The STERRAD VELOCITY™ BI/Process Challenge Device (PCD) contains two important components required for fluorescence readout:

  • α-MUG: a fluorogenic dye activated upon enzymatic reaction with α-glucosidase (AG)
  • α-glucosidase (AG): a natural enzyme, produced by spores
velocity bi details

When the STERRAD VELOCITY™ BI/PCD ampule is crushed, the surviving microorganisms, containing AG, are exposed to a media containing α-MUG. The resulting enzymatic reaction splits α-MUG into 4-MU, a fluorescent compound, and glucose.


If microorganisms survive post-sterilization, the media will fluoresce, indicating a positive BI. Alternatively, in the case that no microorganisms survive after the sterilization cycle, the media will not fluoresce and the BI can be considered negative.

This advancement in readout technology enables sterile processing leaders to establish a greater balance between scaling to clinical demand and increasing the confidence in BI/PCD results prior to releasing instruments.

Automated Record-Keeping Technology for Real-Time Audit Records

In addition to the improved sophistication of rapid-read technology, compliance and record keeping is also enhanced by the STERRAD VELOCITY™ Biological Indicator System's unique connection to STERRAD™ Systems via ASP ACCESS™ Technology Through ASP ACCESS™ Technology, the STERRAD VELOCITY™ Reader integrates with STERRAD™ Sterilizers to automatically correlate sterilizer and BI records, reducing the likelihood of human error and ensuring consistent, complete and AAMI-compliant BI records. This provides confidence in audit-ready BI records to maximise the focus on patient protection.

For more information on STERRAD VELOCITY™ BI/PCD rapid-read technology or automated recording-keeping ability, get a consultation from a sterilization expert.

*Fastest BI/PCD currently marketed for STERRAD™ Sterilization Systems.

**15 or 30 minutes time to results dependent on the software version of the STERRAD VELOCITY™ Reader. Refer to the IFU for actual time to results.



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