Picomolar analysis of proteins using electrophoretically mediated microanalysis and capillary electrophoresis with laser-induced fluorescence detection.
We report a method for the analysis of picomolar concentration proteins using electrophoretically mediated microanalysis (EMMA) to label proteins on-column with a fluorogenic reagent. Labeling is followed by capillary zone electrophoresis separation and postcolumn detection based on laser-induced fluorescence. The method provides a concentration detection limit (3 sigma) of 3 x 10(-13) M for conalbumin. The method provides separation efficiency of 300,000 theoretical plates. Protein extract from a human colon adenocarcinoma cell line generated a dozen major components and many minor components in a 12-min separation; the protein extract from 2.5 cells was used for this analysis. When compared to UV absorbance detection, the EMMA method provides 7,000,000-fold improvement in detection limit.
Lee
I H
IH
Department of Chemistry, University of Alberta, Edmonton, Canada.
Pinto
D
D
Arriaga
E A
EA
Zhang
Z
Z
Dovichi
N J
NJ
D003207:Conalbumin / Q000032:analysis; D019075:Electrophoresis, Capillary / Q000379:methods*; D019073:HT29 Cells; D006801:Humans; D009363:Neoplasm Proteins / Q000032:analysis; D011506:Proteins / Q000032:analysis*; D015203:Reproducibility of Results; D013050:Spectrometry, Fluorescence
D009363:Neoplasm Proteins; D011506:Proteins; D003207:Conalbumin