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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.


Construction and use of lateral flow strips.
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biosensors-03-00360-f003: Construction and use of lateral flow strips.

Mentions: Nitrocellulose (Millipore HiFlow Plus HFB13502) was cut (4 cm × 4 cm) and mounted onto an adhesive backing 8 mm from the edge. Glass fiber pad (Millipore GFCP20300) was cut into a rectangle (10 mm × 4 cm) and mounted on the edge of the backing, overlapping the nitrocellulose by 2 mm. Cellulose (GE Healthcare, CF3) was cut (4 × 4 cm) and mounted on the backing, overlapping the nitrocellulose by 2 mm. The assembly was cut into 4 mm wide strips. Streptavidin was spotted at 4 mg/mL in 0.5 µL aliquots 1 cm above the absorbent pad. A four-fold dilution series of biotinylated BSA in 1% BSA/PBS was prepared, in concentrations ranging from 63 pg/mL to 16 µg/mL. The strips were dipped successively into 20 µL of each concentration of the dilution series, followed by 20 µL of R-PE streptavidin (0.01 mg/mL in 1% BSA/PBS), and then 50 uL 1% BSA/PBS. The solutions were contained in 2.0 mL cylindrical collection tubes (Affymetrix). At each step the liquid was allowed to totally absorb onto the strip before immersion into the next solution. The strips were air-dried and mounted on glass slides. A schematic of the strip construction and use is shown in Figure 3.


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

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

Construction and use of lateral flow strips.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

biosensors-03-00360-f003: Construction and use of lateral flow strips.
Mentions: Nitrocellulose (Millipore HiFlow Plus HFB13502) was cut (4 cm × 4 cm) and mounted onto an adhesive backing 8 mm from the edge. Glass fiber pad (Millipore GFCP20300) was cut into a rectangle (10 mm × 4 cm) and mounted on the edge of the backing, overlapping the nitrocellulose by 2 mm. Cellulose (GE Healthcare, CF3) was cut (4 × 4 cm) and mounted on the backing, overlapping the nitrocellulose by 2 mm. The assembly was cut into 4 mm wide strips. Streptavidin was spotted at 4 mg/mL in 0.5 µL aliquots 1 cm above the absorbent pad. A four-fold dilution series of biotinylated BSA in 1% BSA/PBS was prepared, in concentrations ranging from 63 pg/mL to 16 µg/mL. The strips were dipped successively into 20 µL of each concentration of the dilution series, followed by 20 µL of R-PE streptavidin (0.01 mg/mL in 1% BSA/PBS), and then 50 uL 1% BSA/PBS. The solutions were contained in 2.0 mL cylindrical collection tubes (Affymetrix). At each step the liquid was allowed to totally absorb onto the strip before immersion into the next solution. The strips were air-dried and mounted on glass slides. A schematic of the strip construction and use is shown in Figure 3.

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.