The Product Sterility – Isolator test evaluates samples for sterility by placing them in growth media, incubating them for a minimum of 14 days, and then checking for evidence of microbial contamination. This sterility test is performed in an isolator that has been sterilized with vaporized hydrogen peroxide.
Samples may be tested using either direct transfer or membrane filtration, and using a soybean casein digest broth (soy) or fluid thioglycollate (thio) media, as follows:
USP Method: Samples tested by direct transfer are aseptically immersed in the test media. Samples tested by membrane filtration (liquids, filterable solids, soluble ointments [oils] and sterile-pathway-only devices) are passed through a 0.45µm filter, and the filter is immersed in the test media. A soybean casein digest broth (soy) media is used for aerobic and fungal growth at incubation temperatures of 20 – 25°C or 28 – 32°C. A fluid thioglycollate (thio) media is used for anaerobic growth at an incubation temperature of 30 – 35°C. Sample size is determined both by batch size and individual container fill volumes.
AAMI Method: Samples tested by direct transfer are aseptically immersed in the test media. Soy is used for aerobic and fungal growth at incubation temperatures of 20 – 25°C or 28 – 32°C. Sample size depends on lot size, method used, and bioburden levels.
After a 14-day incubation, samples are evaluated for the presence of turbidity and/or growth. A media transfer and/or confirmation test may be performed. A failure investigation is performed as necessary. Recovered organisms are identified and compared to the organisms that may have been recovered on monitors performed by the test analyst during applicable test sessions. It is determined whether any anomalies occurred on the day of testing, with media sterilization, during sample processing, and/or during shipping.
If you have additional questions about Product Sterility – Isolator test services, or would like to consult with the experts at Nelson Labs, just send us a request or call us at +1 (801) 290-7500.