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ARS Home » Research » Publications at this Location » Publication #185178


item Tu, Shu I
item Gehring, Andrew

Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: 9/30/2005
Publication Date: 10/23/2005
Citation: Tu, S., Gehring, A.G. 2005. Detection of escherichia coli 0157:h7 using immuno beads. SPIE Proceedings. 5996:1-7.

Interpretive Summary:

Technical Abstract: A new fluorescent sandwich method for the detection of Escherichia coli O157:H7 was developed. Streptavidin-coated magnetic beads and fluorescence beads were used to react with biotinylated anti E. coli O157 antibodies to form the immuno magnetic beads (IMB) and immuno fluorescence beads (IFB), respectively. The E. coli bacteria captured by IMB were further labeled with IFB to form IMB (M)-(E. coli O157:H7)(W)-IFB(O) sandwich complexes where M, N and O were integral numbers. Using broth cultured E. coli O157:H7, the sandwich method was able to detect the bacteria at the level of ~ 1000 to 10000 CFU/mL. Known quantity of freshly cultured E. coli O157:H7 cells were added to ground beef obtained from local markets. The bacteria in inoculated beef patties were enriched in EC broth containing novobiocin. After enriched for 4 h at 40 degrees C, the developed IMB-IFB method was applied to detect the presence of E. coli O157:H7. The results demonstrated that the developed method could detect the presence of 1 CFU of E. coli O157:H7 per gram of ground beef.