Abstract: A system for concentrating magnetic particles suspended in a fluid comprising a vessel for containing said fluid having an inner base surface that slopes downwards towards a collection region, the collection region including a retrieval well for collecting magnetic particles; a magnet assembly for positioning under and in proximity with the vessel for attracting magnetic particles to the bottom surface of the vessel, said magnet assembly providing a relatively larger magnetic flux density at a peripheral region thereof; means for laterally traversing the magnet assembly relative to the vessel between a first position whereby the magnet is generally centered under the vessel and a second position whereby the peripheral portion of the magnet is positioned under the well of the vessel; and agitation means for agitating said vessel to facilitate movement of the magnetic particles to the well, where the concentrated particles can be easily removed.

Abstract: A system for concentrating magnetic particles suspended in a fluid comprising a vessel for containing said fluid having an inner base surface that slopes downwards towards a collection region, the collection region including a retrieval well for collecting magnetic particles; a magnet assembly for positioning under and in proximity with the vessel for attracting magnetic particles to the bottom surface of the vessel, said magnet assembly providing a relatively larger magnetic flux density at a peripheral region thereof; means for laterally traversing the magnet assembly relative to the vessel between a first position whereby the magnet is generally centered under the vessel and a second position whereby the peripheral portion of the magnet is positioned under the well of the vessel; and agitation means for agitating said vessel to facilitate movement of the magnetic particles to the well, where the concentrated particles can be easily removed.

Abstract: A process for isolating microorganisms from samples, particularly Shigella spp. from food samples, and a system, apparatus and composition therefor are provided. Magnetic particles are used to capture microorganisms and a system having separate magnetically-based apparatuses for collecting, concentrating and retrieving is used to isolate the magnetic particles having bound microorganisms. The apparatus for concentrating magnetic particles utilizes a small magnet assisted by vibration to concentrate collected particles at a localized region on the bottom of a container. The process, system and apparatus of the present invention are simple and inexpensive providing improved magnetic particle recovery adaptable to large scales.

Abstract: A sampler for determining the microbiological safety or hygienic quality of surfaces comprising a scrubber-retainer which comprises a compressible liquid absorbing elastic element for scrubbing a test surface and releasably retaining a liquid, and a surrounding chamber to confine a region around the scrubber-retainer against the sample surface. The sampler includes a drive mechanism for moving the scrubber-retainer to scrub the test surface and release analytes from the test surface, and alternately compressing and decompressing the compressible material to allow liquid to be alternately released and absorbed, respectively, to produce a suspension of the released analytes.

Abstract: A disposable complete filtration apparatus constructed from a filter means and flexible impermeable film joined together in such manner as to form fluid receptacles for the filtrant and filtrate, said receptacles being connected internally to one another by said filter means. Being preformed, the apparatus requires no assembly by the user. Moreover, by lying flat it occupies negligible space before use and can be dispensed from a roll or stack, yet being flexible it dilates or contracts to accept the sample to be filtered and accomodates the movement of fluid during filtration. In one embodiment the filter means will trap microorganisms and the receiver contains a drinking tube which allows the user to enjoy microbiologically pure water. Chemical or biochemical test reagents may be incorporated into the apparatus so that simple tests requiring filtration and addition of test reagents can be performed automatically.