A capillary electrophoresis laser-induced fluorescence method for analysis of potato glycoalkaloids based on a solution-phase immunoassay. 1. Separation and quantification of immunoassay products.
Solution-phase immunoassays are typically faster and more precise than ELISAs. This research developed a solution-phase for the immunoassay of potato glycoalkaloids (GAs) based on quantification by capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection. Solanidine coupled to 4'-(aminomethyl)fluorescein and a polyclonal antibody solution were used as the immunoreagents. Unbound fluorescent solanidine was detected by CE-LIF (excitation 488 nm, emission 520 nm). Optimum resolution of immunoassay products was achieved with a buffer consisting of 50 mM phosphate, 10% (v/v) methanol, and 1.5 mM SDS, pH 7.5. A plot of signal vs log [GA] produced a sigmoidal curve typical of immunoassays. Analysis of extracts of sprouted Yukon Gold potato tubers and nonsprouted Yukon Gold tubers resulted in total [GA] of 98 microg/g (RSD 9%) and 55 microg/g (RSD 9%), respectively. The findings indicated that CE-LIF coupled with a solution-phase immunoassay can be used to quantify total GA in potatoes.
Driedger
D R
DR
Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5 Canada.
LeBlanc
R J
RJ
LeBlanc
E L
EL
Sporns
P
P
D002240:Carbohydrate Sequence; D004144:Diosgenin; D019075:Electrophoresis, Capillary / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay; D005456:Fluorescent Dyes; D006027:Glycosides / Q000032:analysis* / Q000302:isolation & purification; D007118:Immunoassay; D008969:Molecular Sequence Data; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012991:Solanaceous Alkaloids / Q000032:analysis* / Q000302:isolation & purification; D011198:Solanum tuberosum / Q000737:chemistry*
D005456:Fluorescent Dyes; D006027:Glycosides; D012991:Solanaceous Alkaloids; D004144:Diosgenin; C013255:solanidine