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Portable microfluidic chip for detection of Escherichia coli in produce and blood.

Wang S, Inci F, Chaunzwa TL, Ramanujam A, Vasudevan A, Subramanian S, Chi Fai Ip A, Sridharan B, Gurkan UA, Demirci U - Int J Nanomedicine (2012)

Bottom Line: The microchip showed reliable capture of E. coli in PBS with an efficiency of 71.8% ± 5% at concentrations ranging from 50 to 4,000 CFUs/mL via lipopolysaccharide binding protein.The limits of detection of the microchip for PBS, blood, milk, and spinach samples were 50, 50, 50, and 500 CFUs/mL, respectively.The presented technology can be broadly applied to other pathogens at the POC, enabling various applications including surveillance of food supply and monitoring of bacteriology in patients with burn wounds.

View Article: PubMed Central - PubMed

Affiliation: Bio-Acoustic-MEMS in Medicine Laboratory, Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02139, USA.

ABSTRACT
Pathogenic agents can lead to severe clinical outcomes such as food poisoning, infection of open wounds, particularly in burn injuries and sepsis. Rapid detection of these pathogens can monitor these infections in a timely manner improving clinical outcomes. Conventional bacterial detection methods, such as agar plate culture or polymerase chain reaction, are time-consuming and dependent on complex and expensive instruments, which are not suitable for point-of-care (POC) settings. Therefore, there is an unmet need to develop a simple, rapid method for detection of pathogens such as Escherichia coli. Here, we present an immunobased microchip technology that can rapidly detect and quantify bacterial presence in various sources including physiologically relevant buffer solution (phosphate buffered saline [PBS]), blood, milk, and spinach. The microchip showed reliable capture of E. coli in PBS with an efficiency of 71.8% ± 5% at concentrations ranging from 50 to 4,000 CFUs/mL via lipopolysaccharide binding protein. The limits of detection of the microchip for PBS, blood, milk, and spinach samples were 50, 50, 50, and 500 CFUs/mL, respectively. The presented technology can be broadly applied to other pathogens at the POC, enabling various applications including surveillance of food supply and monitoring of bacteriology in patients with burn wounds.

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Related in: MedlinePlus

(A) Three different food dye solutions were injected into microchannels before performing wash steps. (B) Images of channels before and after wash steps indicated that food dye was removed from microchannels at a flow rate of 2 μL/minute.
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f4-ijn-7-2591: (A) Three different food dye solutions were injected into microchannels before performing wash steps. (B) Images of channels before and after wash steps indicated that food dye was removed from microchannels at a flow rate of 2 μL/minute.

Mentions: By investigating the effects of washing flow rate on E. coli capture efficiency, anti-LBP antibody based surface chemistry was further optimized. At the flow rates of 2, 5, and 10 μL/min, capture efficiencies were 70.7% ± 4%, 60.5% ± 3%, and 53.9% ± 8%, respectively (Figure 3B). Statistical analysis on experimental results indicated that flow rate had a significant effect on capture efficiency (nonparametric Kruskal–Wallis test), where 2 μL/min resulted in significantly greater (P < 0.05) capture efficiency compared to 10 μL/min. The lower efficiency observed at higher flow rates may be related to the correspondingly higher shear stress within the microchannels. Additionally, we used food dyes to visualize and qualitatively analyze the wash steps in microchannels. We observed that the selected flow rate (2 μL/min) achieved effective removal of food dye solution from microchannels (Figure 4).


Portable microfluidic chip for detection of Escherichia coli in produce and blood.

Wang S, Inci F, Chaunzwa TL, Ramanujam A, Vasudevan A, Subramanian S, Chi Fai Ip A, Sridharan B, Gurkan UA, Demirci U - Int J Nanomedicine (2012)

(A) Three different food dye solutions were injected into microchannels before performing wash steps. (B) Images of channels before and after wash steps indicated that food dye was removed from microchannels at a flow rate of 2 μL/minute.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3368510&req=5

f4-ijn-7-2591: (A) Three different food dye solutions were injected into microchannels before performing wash steps. (B) Images of channels before and after wash steps indicated that food dye was removed from microchannels at a flow rate of 2 μL/minute.
Mentions: By investigating the effects of washing flow rate on E. coli capture efficiency, anti-LBP antibody based surface chemistry was further optimized. At the flow rates of 2, 5, and 10 μL/min, capture efficiencies were 70.7% ± 4%, 60.5% ± 3%, and 53.9% ± 8%, respectively (Figure 3B). Statistical analysis on experimental results indicated that flow rate had a significant effect on capture efficiency (nonparametric Kruskal–Wallis test), where 2 μL/min resulted in significantly greater (P < 0.05) capture efficiency compared to 10 μL/min. The lower efficiency observed at higher flow rates may be related to the correspondingly higher shear stress within the microchannels. Additionally, we used food dyes to visualize and qualitatively analyze the wash steps in microchannels. We observed that the selected flow rate (2 μL/min) achieved effective removal of food dye solution from microchannels (Figure 4).

Bottom Line: The microchip showed reliable capture of E. coli in PBS with an efficiency of 71.8% ± 5% at concentrations ranging from 50 to 4,000 CFUs/mL via lipopolysaccharide binding protein.The limits of detection of the microchip for PBS, blood, milk, and spinach samples were 50, 50, 50, and 500 CFUs/mL, respectively.The presented technology can be broadly applied to other pathogens at the POC, enabling various applications including surveillance of food supply and monitoring of bacteriology in patients with burn wounds.

View Article: PubMed Central - PubMed

Affiliation: Bio-Acoustic-MEMS in Medicine Laboratory, Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02139, USA.

ABSTRACT
Pathogenic agents can lead to severe clinical outcomes such as food poisoning, infection of open wounds, particularly in burn injuries and sepsis. Rapid detection of these pathogens can monitor these infections in a timely manner improving clinical outcomes. Conventional bacterial detection methods, such as agar plate culture or polymerase chain reaction, are time-consuming and dependent on complex and expensive instruments, which are not suitable for point-of-care (POC) settings. Therefore, there is an unmet need to develop a simple, rapid method for detection of pathogens such as Escherichia coli. Here, we present an immunobased microchip technology that can rapidly detect and quantify bacterial presence in various sources including physiologically relevant buffer solution (phosphate buffered saline [PBS]), blood, milk, and spinach. The microchip showed reliable capture of E. coli in PBS with an efficiency of 71.8% ± 5% at concentrations ranging from 50 to 4,000 CFUs/mL via lipopolysaccharide binding protein. The limits of detection of the microchip for PBS, blood, milk, and spinach samples were 50, 50, 50, and 500 CFUs/mL, respectively. The presented technology can be broadly applied to other pathogens at the POC, enabling various applications including surveillance of food supply and monitoring of bacteriology in patients with burn wounds.

Show MeSH
Related in: MedlinePlus