In indoor air quality standards, there are two different concepts: "total number of bacteria" and "total number of colonies", and there are essential differences between them, the difference is mainly the type of bacteria measured by these two indicators and their different effects on indoor air quality assessment.
1. What are "total number of bacteria" and "total number of colonies".
1. Total number of bacteria.
The total number of bacteria usually refers to the number of all bacteria that are actually present in the air, regardless of whether they are able to grow under laboratory conditions or not. This number may include live, dormant, dead, and those that cannot grow under standard laboratory conditions. The total bacterial count can be assessed by direct microscopic counting, flow cytometry, or other non-culture techniques.
2. Total number of colonies.
The total number of colonies refers to the number of bacteria that can grow into visible colonies in a particular medium and under specific culture conditions. This value is obtained by inoculating air samples onto culture medium, then incubating them at a suitable temperature for a certain period of time, and counting the visible colonies formed. The total number of colonies includes only those bacteria that can grow under laboratory conditions.
When indoor air quality standards are updated from "total number of colonies" to "total number of bacteria", this means that the evaluation criteria may be more comprehensive and not limited to microflora that can grow under laboratory conditions. This change may be an attempt to more accurately reflect the microbial load in the air, as some bacteria do not grow easily on laboratory media, but they may still have an impact on human health.
In practice, such updates to standards may require the use of different detection techniques and methods. For example, the determination of the total number of bacteria may require the use of more advanced techniques such as cell counting, cell viability assays, or molecular biology methods such as PCR, rather than relying solely on traditional culture methods. Such a shift could have an impact on air quality monitoring and control strategies, requiring higher technical standards and potentially stricter controls.
2. Advanced air detection technology.
With its long-standing expertise in microbiological quality control, Sartorius can help you optimize your testing and improve process safety, as well as achieve consistent, repeatable and reliable results in process and final release tests to meet your current and future needs. The Sartorius MD8 AirScan air detector can be used to monitor live microorganisms in the air in cleanrooms and controlled areas in (C) GMP environments. With the help of a gel film, the MD8 AirScan provides active air monitoring for at least 8 hours without interruption. exclude false-negative results; This proprietary, USP-approved gel membrane retains even the smallest airborne microorganisms and maximizes their viability.
The MD8 AirScan control unit is made of plastic material PA6 with 30% glass fiber, and the unit weighs only 12kg（2.6lbs）。It includes 2 LEDs for displaying working status and errors, stores test results from up to 300 different sampling heads, and has a port to connect to a thermal transfer printer. It is equipped with a quick connector for quick connection to the sampling head.