Settling Plates (Petrifilm) vs. MB-2Air sampling must be reproducible to be an effective tool to measure before and after microbiological treatments. Settling plates are not an effective tool, specifics are given below. The MB-2 self contained programmable unit is the sampler of choice due to the fact that it draws a set amount of air (from 10 to 500 liters) in any environment (turbulent, etc.). Objective measurement coupled with spatial mapping gives the requisite tools for monitoring the processing environment as well as monitoring treatment efforts. The following information further elucidates the difference of these two sampling methods. Settling Plates are the simplest way of collecting airborne biological particles. A petri dish containing agar medium (or hydrated Petrifilm™) collects particles that settle by gravity. It is passive, non volumetric, and imprecise; it over-represents larger particles because of their rapid settling rate. Collection in turbulent air is seriously affected by shadowing or turbulent deposition. Sampling reproducibility is also questionable, therefore, profiling of a facility or production area are ... MB-2 is self-contained, programmable, battery-operated portable unit that has seen many enhancements over the past several years. Numerous industries have adopted it as a standard, and the MB-2 is one of the two sampler mentioned by name in Microbiological Evaluation of Clean Rooms and Other Controlled Environments, the 1998 USP 23-NF 24 Eighth Supplement, Section 1116. The MB-2 sampler uses inexpensive contact plates and is traceable to the National Institute of Standards and Technology. The enhancements and accessories made for the basic model allow for sampling in many different environments and under many different environmental conditions. This flexibility makes the MB-2 sampler a versatile and excellent screening tool for airborne microbes. |