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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Quality and Safety Assessment Research Unit » Research » Publications at this Location » Publication #338982

Research Project: Develop Rapid Optical Detection Methods for Food Hazards

Location: Quality and Safety Assessment Research Unit

Title: Particle size related bacterial recovery in immunomagnetic separation

item CHEN, JING - US Department Of Agriculture (USDA)
item Park, Bosoon

Submitted to: American Chemical Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 2/13/2017
Publication Date: 4/2/2017
Citation: Chen, J., Park, B. 2017. Particle size related bacterial recovery in immunomagnetic separation. American Chemical Society Abstracts. ACS.

Interpretive Summary: none.

Technical Abstract: Magnetic nanoparticles (MNPs) have demonstrated superior capture efficiencies in small molecule targets during immunomagnetic separation (IMS), but the potentials of MNPs in bacterial isolation have not been verified. The objective of this study was to evaluate the effect of magnetic particle size on the recovery of target pathogens and non-specific binding of interfering bacteria. Iron oxide particles of 100 nm, 500 nm, and 1 µm were functionalized with anti-Salmonella antibodies for IMS of S. Enteritidis. Subsequent plate counts suggest that 100 nm and 1 µm magnetic particles yielded similar recovery rates of Salmonella, whereas 500 nm particles demonstrated consistently higher recovery across a wide contamination level range (50-5x107 CFU/mL). Meanwhile, no significant difference in the non-specific binding of E. coli was observed for particles of different sizes. Continued investigations in food matrices will provide insights for maximized isolation of target pathogens from the sample matrix and competitive microflora and allow for higher accuracies in downstream detection.