title: Low-density lipoprotein analysis in microchip capillary electrophoresis systems.
abstract: Due to the mounting evidence for altered lipoprotein and cholesterol-lipoprotein content in several disease states, there has been an increasing interest in analytical methods for lipoprotein profiling for diagnosis. The separation of low- and high-density lipoproteins (LDL and HDL, respectively) has been recently demonstrated using a microchip capillary electrophoresis (CE) system [1]. In contrast to this previous study, the present report demonstrates that LDL analysis can be performed in an uncoated glass microchannel. Moreover, by adding sodium dodecyl sulfate (SDS) to the sample at a concentration well below the critical micellar concentration prior to injection, the LDL peak undergoes a focusing effect and exhibits an apparent efficiency of 2.2 x 10(7) plates/m. Laser light scattering experiments demonstrate that the low concentration of SDS used does not significantly alter lipoprotein particle size distribution within the time course that the analysis is performed. It is thus hypothesized that SDS nondisruptively coats LDL particles. The peak sharpening effect, observed only when SDS is added solely to the sample, is probably due to a mobility gradient created between the sample and the running buffer. The chip-based method demonstrated here has the potential for rapid analysis and sensitive detection of different LDL forms of clinical relevance.
authors.affiliation: Institute of Microtechnology, University of Neuchâtel, Rue Jacquet-Droz 1, CH-2007 Neuchâtel, Switzerland.
authors.forename: Laura
authors.initials: L
authors.lastname: Ceriotti
authors.forename: Takayuki
authors.initials: T
authors.lastname: Shibata
authors.forename: Britta
authors.initials: B
authors.lastname: Folmer
authors.forename: Bruce H
authors.initials: BH
authors.lastname: Weiller
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Roberts
authors.forename: Nico F
authors.initials: NF
authors.lastname: de Rooij
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Verpoorte
mesh_terms: D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008027:Light; D008075:Lipoproteins, HDL / Q000032:analysis / Q000187:drug effects / Q000302:isolation & purification; D008077:Lipoproteins, LDL / Q000032:analysis* / Q000187:drug effects / Q000302:isolation & purification; D008904:Miniaturization; D012542:Scattering, Radiation; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology
chemical_list: D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D012967:Sodium Dodecyl Sulfate