Cardiff Metropolitan University
Proof of Concept Containment Systems that Prevent Freeze Dryer Contamination-Cherry C.pdf (269.16 kB)

Proof of concept: containment systems that prevent freeze-drier contamination when lyophilising Escherichia coli (JM 109)

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posted on 2022-05-20, 14:25 authored by Christopher Lee Albert Cherry, Rose Cooper, Huw Millward, John Landon

 This study describes the use of containment systems to prevent escape of microorganisms during lyophilization, thereby avoiding contamination of freeze-drying equipment. Cultures of Escherichia coli (JM 109) of an approximate cell concentration of 109 cfu/mL were suspended in 0.9% saline, aseptically dispensed into vials, double-wrapped in either medical-grade paper or Tyvek sterilization pouches and freeze-dried. An intentional collapse phenomenon was observed during the freeze-drying process, ejecting debris and aerosols from the vials, thus representing a worst-case challenge for containment. Following freeze drying, the layers of the pouches were tested for microbial contamination using 3 M Clean-Trace sur- face ATP analyzer swabs, surface swabs, and tryptone soya agar contact plates. The paper and Tyvek pouches were able to contain a maximum cell concentration of 1 x 106 cfu/mL of E. coli recov- ered from ejected debris. Some penetration through the first paper pouch layer was observed (although not Tyvek); however, this was successfully retained by the second, outer layer preventing contami- nation of the lyophilization apparatus and laboratory environment. 


Knowledge Economy Skills Scholarship (KESS)


Published in

Drying Technology


Taylor & Francis


  • AM (Accepted Manuscript)


Cherry, C.L.A., Cooper, R., Millward, H. and Landon, J. (2015) 'Proof of concept: containment systems that prevent freeze-dryer contamination when lyophilizing Escherichia coli (JM 109)', Drying Technology, 33(4), pp.466-470

Electronic ISSN


Cardiff Met Affiliation

  • Cardiff School of Sport and Health Sciences

Cardiff Met Research Centre/Group

  • Microbiology & Infection

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  • © The Publisher


  • en

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