Updated Jul 2009
PULSIFIER® for preparing sample suspensions with low debris levels
(e.g., for microbiological tests by membrane filter, PCR or other rapid analytical method)
The Pulsifier® (invented by Dr. Tony Sharpe of Filtaflex Ltd.) brought a new principle to the preparation of microbial suspensions. Instead of the familiar paddle action which crushes samples, Pulsifier® beats the outside of the bag at high-frequency, producing a combination of shock waves and intense stirring that drives microbes into suspension while causing minimal sample dispersion. Suspensions containing reduced levels of food detritus are ideal starting points for modern rapid methods of analysis. Thorough evaluations have shown that:
- microbial counts such as Total Aerobes, coliforms, and Escherichia coli (biotype 1) prepared by Pulsifier do not differ significantly from those prepared by a paddle-type blender;
- the reduced levels of suspended debris in suspensions prepared by Pulsifier can dramatically improve debris-related effects such as filtration rates;
- Pulsifying is an ISO method (ISO 7218:2007(E) - "Microbiological Examination of Foods and Animal Feedingstuffs").
Several features distinguish the Pulsifier from paddle-type blenders. Because the action does not require the sample and bag to get crushed against a strong, solid wall (the blender "Door") the Pulsifier Door can be transparent to allow a full view of the sample's progress. The Pulsifier Door contains the complete bag-clamping mechanism (there is no lever to pull) - push the Door against the machine to clamp a bag, insert a finger behind the Door to unclamp it. The leverless action also allows the Door to be lifted out completely in the event the machine requires cleaning.
Pulsifier sales are now handled by Microgen Bioproducts, Ltd., UK - microgenbioproducts.com
For specific advice on Pulsifier performance and applications contact Filtaflex Ltd
References
Sharpe, A.N. Hearn, E.M. and Kovacs-Nolan, J. 2000. Membrane filtration rates and HGMF coliform and Escherichia coli counts in food suspensions by Pulsifier®.J. Food Prot., 63: 126-130.
Fung, D.Y.C., A.N. Sharpe, B.C. Hart and Y. Liu 1998. The Pulsifier: a new instrument for preparing food suspensions for microbiological analysis. J. Rapid Meth. Autom. Microbiol., 6: 43-49.
Kang, D-H, R.H. Dougherty and D.Y.C. Fung. 2001. Comparison of Pulsifier® and Stomacher® to detach microorganisms from lean meat tissues. J. Rapid. Meth. Autom. Microbiol., 9: 27-32.
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