A microwave-powered sterilizable interface for aseptic access to bioreactors that are vulnerable to microbial contamination

Novel methods and apparatus that employ the rapid heating characteristics o f microwave irradiation to facilitate the aseptic transfer of nutrients, pr oducts, and other materials between microbially sensitive systems and the e xternal environment are described. The microwave-sterilizable access port ( MSAP) consists of a 600-W magnetron emitting at a frequency of 2.45 GHz, a sterilization chamber with inlet and outlet flow lines, and a specimen tran sfer interface. Energy is routed to the sterilization chamber via a coaxial transmission line where small quantities of water couple strongly with the incident radiation to produce a superheated vapor phase. The efficiency of energy transfer is enhanced through the use of microwave susceptors within the sterilization chamber. Mating surfaces are thermally sterilized throug h direct contact with the hot gas. Efficacy has been demonstrated using the thermophile Bacillus stearothermophilus.