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Improving sensitivity in micro‐free flow electrophoresis using signal averaging
Author(s) -
Turgeon Ryan T.,
Bowser Michael T.
Publication year - 2009
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200800497
Subject(s) - signal (programming language) , sensitivity (control systems) , electrophoresis , analyte , signal averaging , free flow electrophoresis , microfluidics , flow (mathematics) , analytical chemistry (journal) , biological system , chromatography , materials science , chemistry , computer science , mathematics , nanotechnology , analog signal , digital signal processing , electronic engineering , engineering , geometry , signal transfer function , enzyme , biology , biochemistry , polyacrylamide gel electrophoresis , programming language , gel electrophoresis of proteins , computer hardware
Microfluidic free‐flow electrophoresis (μFFE) is a separation technique that separates continuous streams of analytes as they travel through an electric field in a planar flow channel. The continuous nature of the μFFE separation suggests that approaches more commonly applied in spectroscopy and imaging may be effective in improving sensitivity. The current paper describes the S / N improvements that can be achieved by simply averaging multiple images of a μFFE separation; 20–24‐fold improvements in S / N were observed by averaging the signal from 500 images recorded for over 2 min. Up to an 80‐fold improvement in S / N was observed by averaging 6500 images. Detection limits as low as 14 pM were achieved for fluorescein, which is impressive considering the non‐ideal optical set‐up used in these experiments. The limitation to this signal averaging approach was the stability of the μFFE separation. At separation times longer than 20 min bubbles began to form at the electrodes, which disrupted the flow profile through the device, giving rise to erratic peak positions.