Membrane Filtration
 Direct transfer methods such as bacteriostasis/fungistasis testing via product immersion are most commonly recommended for sterility testing of medical devices. However, the U.S. FDA has found membrane filtration an acceptable alternative when the device may contain or be coated with some inhibitor, such as preservative or drug product, that interferes with microbial growth.
In this procedure, the device is rinsed, and the rinse liquid passed through small-membrane filter paper. The paper is then placed into media selected to encourage growth of any accompanying bacteria or fungi.
Membrane filtration testing requires many more manipulations than direct immersion. This makes it inherently more costly.
More manipulations also make this process more open to contamination. However, unlike some laboratories, Microtest employs advanced Millipore Steritest™ and Sterisolutest™ products for important aspects of its membrane filtration work. These offer a closed-system testing method. With no need to open containers or directly manipulate membranes, the risk of adventitious contamination is greatly reduced.
|
