title: Analysis of parasites by electrorotation.
abstract: OBJECTIVE
  The application of the AC electrokinetic technique of electrorotation for studying eukaryotic parasite transmission stages is reviewed. Electrorotation is a noninvasive technique that utilizes electrically energized microelectrode structures within micro-fluidic chambers to probe the physiological structure of micro-organisms. Application of the technique to the transmission life cycle stages of three separate genera of protozoan parasites, Cryptosporidium, Giardia and Cyclospora, and one nematode genus Ascaris, each of significant public health importance, is described.
  
  
  RESULTS
  Standard electrorotation apparatus, consisting of micro-fabricated electrodes in a fluidic chip, quadrature sinusoidal signal generator, microscope and image capture system, was used to study each organism. Spectra of cellular rotation rate were recorded as a function of applied electric field frequency and compared with standardized biological tests, where appropriate, to illustrate the effectiveness and versatility of the electrorotation technique.
  
  
  CONCLUSIONS
  Electrorotational determination of the viability of individual G. intestinalis cysts, Cryptosporidium parvum and Cyclospora cayetanensis oocysts has been achieved. The sporulation state of Cyclospora cayetanensis oocysts was also readily determined, as was the fertilization state of A. suum ova.
  
  
  CONCLUSIONS
  Electrorotation is a simple, noninvasive and versatile analytical technique suited to a wide range of particle types and capable of incorporation into integrated Lab-on-a-chip devices.
authors.affiliation: Institute of Bioelectronic and Molecular Microsystems, University of Wales, Bangor, Gwynedd, UK. colin@informatics.bangor.ac.uk
authors.forename: C
authors.initials: C
authors.lastname: Dalton
authors.forename: A D
authors.initials: AD
authors.lastname: Goater
authors.forename: J P H
authors.initials: JP
authors.lastname: Burt
authors.forename: H V
authors.initials: HV
authors.lastname: Smith
mesh_terms: D000818:Animals; D003458:Cryptosporidium / Q000502:physiology; D021744:Cyclospora / Q000502:physiology; D004574:Electromagnetic Fields; D005872:Giardia / Q000502:physiology; D008839:Microelectrodes; D008904:Miniaturization / Q000379:methods; D010271:Parasites / Q000502:physiology*; D010274:Parasitology / Q000379:methods; D012399:Rotation