The techniques available for the microbiological monitoring of products and manufacturing environments have come a long way in the last few decades. Even though enumerating microbial cells by counting colonies on an agar filled Petri dish is still a common technique, a variety of more sophisticated and rapid methods are making their way into the quality control microbiology laboratory. These Rapid Microbiological Methods (RMM) exploit chemical and physical methods developed to elucidate the structure of cell components and the functions of biomolecules. These methods are then applied to the detection, enumeration, and identification of microorganisms that may be present in pharmaceutical, food and beverage, water and other samples submitted to the quality control labs. Thus, the simple view of a bacterial cell as a tiny living entity so small as to be invisible to the naked eye, and countable only by either microscopy or culture, is changing to a much more complex picture encompassing the most intimate details of the cell structure and the biomolecules that form it.

Microbiological controls of the environment in clean rooms are now included in most recommendations and regulatory documents. For example, in the guide “Bonnes Pratiques de Fabrication (BPF)”(1) it is recommended that limits and values of microorganisms in the air and on the surfaces are applied in the different clean room classes (A-D). This guide is the French translation of the guide for European Good Manufacturing Practice (2). In the hospital environment, the French standard NF390351 imposes microbiological values of the air and surfaces based on defined risk environments.