title: Polymer microchip CE of proteins either off- or on-chip labeled with chameleon dye for simplified analysis.
abstract: Microchip CE of proteins labeled either off- or on-chip with the "chameleon" CE dye 503 using poly(methyl methacrylate) microchips is presented. A simple dynamic coating using the cationic surfactant CTAB prevented nonspecific adsorption of protein and dye to the channel walls. The labeling reactions for both off- and on-chip labeling proceeded at room temperature without requiring heating steps. In off-chip labeling, a 9 ng/mL concentration detection limit for BSA, corresponding to a approximately 7 fg (100 zmol) mass detection limit, was obtained. In on-chip tagging, the free dye and protein were placed in different reservoirs of the microchip, and an extra incubation step was not needed. A 1 microg/mL concentration detection limit for BSA, corresponding to a approximately 700 fg (10 amol) mass detection limit, was obtained from this protocol. The earlier elution time of the BSA peak in on-chip labeling resulted from fewer total labels on each protein molecule. Our on-chip labeling method is an important part of automation in miniaturized devices.
authors.affiliation: Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA.
authors.forename: Ming
authors.initials: M
authors.lastname: Yu
authors.forename: Hsiang-Yu
authors.initials: HY
authors.lastname: Wang
authors.forename: Adam T
authors.initials: AT
authors.lastname: Woolley
mesh_terms: D000327:Adsorption; D004396:Coloring Agents / Q000737:chemistry*; D019075:Electrophoresis, Capillary / Q000379:methods*; D056656:Lab-On-A-Chip Devices; D057230:Limit of Detection; D008856:Microscopy, Fluorescence; D008904:Miniaturization; D011108:Polymers / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000032:analysis
chemical_list: D004396:Coloring Agents; D011108:Polymers; D012710:Serum Albumin, Bovine