Improvement of the immunomagnetic separation method selective for Escherichia coli O157 strains - PubMed (original) (raw)

Improvement of the immunomagnetic separation method selective for Escherichia coli O157 strains

T Tomoyasu. Appl Environ Microbiol. 1998 Jan.

Abstract

Immunomagnetic separation is a useful enrichment method selective for Escherichia coli O157 cells against non-O157 E. coli cells from a preenrichment culture. However, E. coli cells are adsorbed onto a solid surface nonspecifically. With the conventional immunomagnetic separation method, this nonspecific adsorption interfered with immunomagnetic separation. It was found that this interference could be reduced with a low-ionic-strength solution. When immunomagnetic separation was carried out with this solution, the proportion of E. coli O157 cells to non-O157 E. coli cells increased from 9.6 to 31.4 times compared to the proportion obtained by the conventional immunomagnetic separation method. The effectiveness of this solution was successfully evaluated by the use of E. coli O157-spiked samples.

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Figures

FIG. 1

FIG. 1

Procedure for measurement of adsorption ability of E. coli onto Dynabeads.

FIG. 2

FIG. 2

Procedure for IMS selective for E. coli O157.

FIG. 3

FIG. 3

Procedure for isolation of E. coli O157 from the spiked minced beef.

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