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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.


Absorbance lateral flow images and plot. The strips were spotted with streptavidin. Dilutions of biotinylated BSA, followed by gold-labeled streptavidin, followed by buffer were absorbed on the strips. Each concentration was tested in triplicate. Images were obtained with the camera of an iPhone 4. Image analysis was done with Image J and the results plotted. A sample of the images is shown on the right.
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biosensors-03-00360-f007: Absorbance lateral flow images and plot. The strips were spotted with streptavidin. Dilutions of biotinylated BSA, followed by gold-labeled streptavidin, followed by buffer were absorbed on the strips. Each concentration was tested in triplicate. Images were obtained with the camera of an iPhone 4. Image analysis was done with Image J and the results plotted. A sample of the images is shown on the right.

Mentions: Figure 7 shows the analogous assay with the substitution of colloidal gold for the R-PE on streptavidin and flash photography instead of fluorescence detection. Compared to the fluorescence assay, the absorbance assay has a narrower useful concentration range as well as a less sensitive limit of detection. The absorbance data has a dynamic range of 16–4,000 ng/mL of biotinylated BSA; the signal is not a linear function of concentration. The dynamic range of the signal is also smaller; the difference between the highest and the lowest signal is only 10-fold. The prozone effect is observed at 16,000 ng/mL as much reduced signal.


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

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

Absorbance lateral flow images and plot. The strips were spotted with streptavidin. Dilutions of biotinylated BSA, followed by gold-labeled streptavidin, followed by buffer were absorbed on the strips. Each concentration was tested in triplicate. Images were obtained with the camera of an iPhone 4. Image analysis was done with Image J and the results plotted. A sample of the images is shown on the right.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

biosensors-03-00360-f007: Absorbance lateral flow images and plot. The strips were spotted with streptavidin. Dilutions of biotinylated BSA, followed by gold-labeled streptavidin, followed by buffer were absorbed on the strips. Each concentration was tested in triplicate. Images were obtained with the camera of an iPhone 4. Image analysis was done with Image J and the results plotted. A sample of the images is shown on the right.
Mentions: Figure 7 shows the analogous assay with the substitution of colloidal gold for the R-PE on streptavidin and flash photography instead of fluorescence detection. Compared to the fluorescence assay, the absorbance assay has a narrower useful concentration range as well as a less sensitive limit of detection. The absorbance data has a dynamic range of 16–4,000 ng/mL of biotinylated BSA; the signal is not a linear function of concentration. The dynamic range of the signal is also smaller; the difference between the highest and the lowest signal is only 10-fold. The prozone effect is observed at 16,000 ng/mL as much reduced signal.

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.