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A low-cost, high-performance system for fluorescence lateral flow assays.

Lee LG, Nordman ES, Johnson MD, Oldham MF - Biosensors (Basel) (2013)

Bottom Line: A wide range of values for the ratio of signal to nonspecific binding was found, from 50 for R-phycoerythrin (R-PE) to 0.15 for Brilliant Violet 605.Fluorescence detection with R-PE and absorbance detection with colloidal gold were directly compared in lateral flow using biotinylated bovine serum albumen (BSA) as the analyte.We believe our inexpensive yet high-performance platform will be useful for providing quantitative and sensitive detection in a point-of-care setting.

View Article: PubMed Central - PubMed

Affiliation: Song Diagnostic Research LLC, 1 Megans Lane, Woodside, CA 94062, USA. Linda@songdx.net.

ABSTRACT
We demonstrate a fluorescence lateral flow system that has excellent sensitivity and wide dynamic range. The illumination system utilizes an LED, plastic lenses and plastic and colored glass filters for the excitation and emission light. Images are collected on an iPhone 4. Several fluorescent dyes with long Stokes shifts were evaluated for their signal and nonspecific binding in lateral flow. A wide range of values for the ratio of signal to nonspecific binding was found, from 50 for R-phycoerythrin (R-PE) to 0.15 for Brilliant Violet 605. The long Stokes shift of R-PE allowed the use of inexpensive plastic filters rather than costly interference filters to block the LED light. Fluorescence detection with R-PE and absorbance detection with colloidal gold were directly compared in lateral flow using biotinylated bovine serum albumen (BSA) as the analyte. Fluorescence provided linear data over a range of 0.4-4,000 ng/mL with a 1,000-fold signal change while colloidal gold provided non-linear data over a range of 16-4,000 ng/mL with a 10-fold signal change. A comparison using human chorionic gonadotropin (hCG) as the analyte showed a similar advantage in the fluorescent system. We believe our inexpensive yet high-performance platform will be useful for providing quantitative and sensitive detection in a point-of-care setting.

No MeSH data available.


Images and plot of absorbance lateral flow analysis of hCG. Lateral flow strips were spotted with goat anti-hCG, then dipped successively in a dilution series of hCG, followed by gold streptavidin mixed with biotinylated mouse anti-hCG, followed by buffer. Each concentration of hCG was tested in triplicate.
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biosensors-03-00360-f009: Images and plot of absorbance lateral flow analysis of hCG. Lateral flow strips were spotted with goat anti-hCG, then dipped successively in a dilution series of hCG, followed by gold streptavidin mixed with biotinylated mouse anti-hCG, followed by buffer. Each concentration of hCG was tested in triplicate.

Mentions: Analysis of human chorionic gonadotropin (hCG) was also performed with the simplified lateral flow system with both fluorescence and absorbance measurement. The sandwich system for fluorescence consisted of polyclonal goat anti hCG spotted on the strip, anti hCG as the analyte, and biotinylated mouse monoclonal anti hCG mixed with R-PE streptavidin. The results of testing strips in a four-fold dilution series are shown in Figure 8. The prozone effect is evident at 1,000 ng/mL with a non-linear data point. Evidence of the pipette tip used for spotting the goat antibody appears as a fluorescent spot, perhaps due to a high local concentration of antibody. The titration with absorbance measurement using biotinylated mouse monoclonal anti-hCG mixed with gold-labeled streptavidin is shown in Figure 9. As before, the fluorescence measurement shows both greater sensitivity and dynamic range than the absorbance measurement.


A low-cost, high-performance system for fluorescence lateral flow assays.

Lee LG, Nordman ES, Johnson MD, Oldham MF - Biosensors (Basel) (2013)

Images and plot of absorbance lateral flow analysis of hCG. Lateral flow strips were spotted with goat anti-hCG, then dipped successively in a dilution series of hCG, followed by gold streptavidin mixed with biotinylated mouse anti-hCG, followed by buffer. Each concentration of hCG was tested in triplicate.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4263565&req=5

biosensors-03-00360-f009: Images and plot of absorbance lateral flow analysis of hCG. Lateral flow strips were spotted with goat anti-hCG, then dipped successively in a dilution series of hCG, followed by gold streptavidin mixed with biotinylated mouse anti-hCG, followed by buffer. Each concentration of hCG was tested in triplicate.
Mentions: Analysis of human chorionic gonadotropin (hCG) was also performed with the simplified lateral flow system with both fluorescence and absorbance measurement. The sandwich system for fluorescence consisted of polyclonal goat anti hCG spotted on the strip, anti hCG as the analyte, and biotinylated mouse monoclonal anti hCG mixed with R-PE streptavidin. The results of testing strips in a four-fold dilution series are shown in Figure 8. The prozone effect is evident at 1,000 ng/mL with a non-linear data point. Evidence of the pipette tip used for spotting the goat antibody appears as a fluorescent spot, perhaps due to a high local concentration of antibody. The titration with absorbance measurement using biotinylated mouse monoclonal anti-hCG mixed with gold-labeled streptavidin is shown in Figure 9. As before, the fluorescence measurement shows both greater sensitivity and dynamic range than the absorbance measurement.

Bottom Line: A wide range of values for the ratio of signal to nonspecific binding was found, from 50 for R-phycoerythrin (R-PE) to 0.15 for Brilliant Violet 605.Fluorescence detection with R-PE and absorbance detection with colloidal gold were directly compared in lateral flow using biotinylated bovine serum albumen (BSA) as the analyte.We believe our inexpensive yet high-performance platform will be useful for providing quantitative and sensitive detection in a point-of-care setting.

View Article: PubMed Central - PubMed

Affiliation: Song Diagnostic Research LLC, 1 Megans Lane, Woodside, CA 94062, USA. Linda@songdx.net.

ABSTRACT
We demonstrate a fluorescence lateral flow system that has excellent sensitivity and wide dynamic range. The illumination system utilizes an LED, plastic lenses and plastic and colored glass filters for the excitation and emission light. Images are collected on an iPhone 4. Several fluorescent dyes with long Stokes shifts were evaluated for their signal and nonspecific binding in lateral flow. A wide range of values for the ratio of signal to nonspecific binding was found, from 50 for R-phycoerythrin (R-PE) to 0.15 for Brilliant Violet 605. The long Stokes shift of R-PE allowed the use of inexpensive plastic filters rather than costly interference filters to block the LED light. Fluorescence detection with R-PE and absorbance detection with colloidal gold were directly compared in lateral flow using biotinylated bovine serum albumen (BSA) as the analyte. Fluorescence provided linear data over a range of 0.4-4,000 ng/mL with a 1,000-fold signal change while colloidal gold provided non-linear data over a range of 16-4,000 ng/mL with a 10-fold signal change. A comparison using human chorionic gonadotropin (hCG) as the analyte showed a similar advantage in the fluorescent system. We believe our inexpensive yet high-performance platform will be useful for providing quantitative and sensitive detection in a point-of-care setting.

No MeSH data available.