Automated large-volume sample stacking procedure to detect labeled peptides at picomolar concentration using capillary electrophoresis and laser-induced fluorescence detection.
We have developed an automated large-volume sample stacking (LVSS) procedure to detect fluorescein isothiocyanate-labeled peptides in the picomolar range. The injection duration is 10 min at 50 mbar to fill 62% of the capillary volume to the detection cell. The calculated limit of detection (S/N=3), filling 1% of the capillary volume, is 74 pM for bradykinin and 45 pM for L-enkephalin with samples diluted in water and analyzed in a 50 mM borate buffer, pH 9.2. With the automated LVSS system, the limits of detection are 7 pM for bradykinin, 3 pM for L-enkephalin and 2 pM for substance P. LVSS is shown to be quantitative from 500 to 10 pM.
Siri
Nathalie
N
Picometrics, 10 Avenue de l'Europe, 31520 Ramonville, France.
Riolet
Pierre
P
Bayle
Christophe
C
Couderc
François
F
D001331:Automation; D019075:Electrophoresis, Capillary / Q000379:methods*; D007834:Lasers; D010455:Peptides / Q000032:analysis*; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods*
D010455:Peptides