Pros and Cons of Cleanroom Microbe Detection Devices

Traditional methods of detecting and correcting the presence of viable particles in a cleanroom can be lengthy. If present, viable particles can result in weeks of lost manufacturing time. However, non-traditional microbe detection significantly hastens the process of detecting and correcting the presence of viable particles. As with anything, there are downsides to these options, as well. Here is a brief comparison of options.


  • Plates. Several methods use plates that are put in areas of interest (high-risk) around the cleanroom. The plates collect particles in the air for several hours. Then the plates are collected, incubated, and after colonization, identified and counted based on the surface area of the plate. This process takes 3-7 days, during which the microorganisms will only continue to grow.
  • Air samplers. This is a more active means of collection, resulting in a better sample. Filter membranes, agar strips, or contact plates are used to collect particles through impaction. It works in a way that doesn’t disrupt the normal airflow and doesn’t render biological particles non-viable. This, too, takes time to colonize and count particles, however.

Both of these methods are less expensive, but take a significant amount of time.


  • Laser particle counters. There are a variety of these on the market. The lasers cause biological particles to fluoresce as they pass through the beam. Photo-sensitive optics detect the light and count the particles. It is possible to separate the counts into viable and non-viable data. These counters don’t identify the microorganisms like the traditional methods do. Lab analysis is still required; however, these counters offer real-time monitoring. Investigation is simpler and faster, leading to earlier corrective action. In fact, it’s feasible that they can detect viables early enough to prevent an incident. The greatest down side of these counters is cost.
  • Portable microbe sensors. These, too, uses photo-sensitive optics to measure the volume of fluorescing particles. They heat up captured particles to get them to glow, so it isn’t completely in real-time, but it is close. This method does not identify viables, and there is no particle count. They are less expensive than laser particle counters, and really are best used as an early warning detection system.

When comparing methods of microbe detection, consider how long it would take to detect a breach, investigate the source, and then verify the effectiveness of remediation. If the time factor with a traditional system devastates your operation, it may be worth investing in a more sophisticated, real-time particle counter. If you have questions about cleanroom validation, certification, or manufacturing, contact Gerbig Engineering Company. We are experts with nearly 30 years of experience.  Call us at 888-628-0056 or email

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