title: Flow-through immunomagnetic separation system for waterborne pathogen isolation and detection: application to Giardia and Cryptosporidium cell isolation.
abstract: Simultaneous sample washing and concentration of two waterborne pathogen samples were demonstrated using a rotational magnetic system under continuous flow conditions. The rotation of periodically arranged small permanent magnets close to a fluidic channel carrying magnetic particle suspension allows the trapping and release of particles along the fluidic channel in a periodic manner. Each trapping and release event resembles one washing cycle. The performance of the magnetic separation system (MSS) was evaluated in order to test its functionality to isolate magnetic-labelled protozoan cells from filtered, concentrated tap water, secondary effluent water, and purified water. Experimental protocols described in US Environmental Protection Agency method 1623 which rely on the use of a magnetic particle concentrator, were applied to test and compare our continuous flow cell separation system to the standard magnetic bead-based isolation instruments. The recovery efficiencies for Giardia cysts using the magnetic tube holder and our magnetic separation system were 90.5% and 90.1%, respectively, from a tap water matrix and about 31% and 18.5%, respectively, from a spiked secondary effluent matrix. The recovery efficiencies for Cryptosporidium cells using the magnetic tube holder and our magnetic separation system were 90% and 83.3%, respectively, from a tap water matrix and about 38% and 36%, respectively, from a spiked secondary effluent matrix. Recoveries from all matrices with the continuous flow system were typically higher in glass tubing conduits than in molded plastic conduits.
authors.affiliation: Bioelectronics Program, Institute of Microelectronics, 11 Science Park Road, Singapore 117685, Singapore. qasem.alramadan@epfl.ch
authors.forename: Qasem
authors.initials: Q
authors.lastname: Ramadan
authors.forename: Lay
authors.initials: L
authors.lastname: Christophe
authors.forename: William
authors.initials: W
authors.lastname: Teo
authors.forename: ShuJun
authors.initials: S
authors.lastname: Li
authors.forename: Han Hua
authors.initials: HH
authors.lastname: Feng
mesh_terms: D003458:Cryptosporidium / Q000302:isolation & purification*; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods; D004867:Equipment Design; D005872:Giardia / Q000302:isolation & purification*; D018189:Immunomagnetic Separation / Q000295:instrumentation* / Q000379:methods; D014867:Water / Q000032:analysis / Q000469:parasitology*; D014881:Water Supply / Q000032:analysis
chemical_list: D014867:Water