PREVENTION OF CROSS-REACTIONS IN THE ENZYME LINKED IMMUNOSORBENT ASSAY (ELISA) FOR THE DETECTION OF STAPHYLOCOCCUS AUREUS ENTEROTOXIN TYPE B IN CULTURE FILTRATES AND FOODS

Authors

  • J. W. KOPER,

    1. Laboratory for Zoonoses and Food Microbiology and Unit for Immunochemistry National Institute of Public Health P. O. Box 1, Bilthoven The Netherlands
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  • A. M. HAGENAARS,

    1. Laboratory for Zoonoses and Food Microbiology and Unit for Immunochemistry National Institute of Public Health P. O. Box 1, Bilthoven The Netherlands
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  • S. NOTERMANS

    Corresponding author
    1. Laboratory for Zoonoses and Food Microbiology and Unit for Immunochemistry National Institute of Public Health P. O. Box 1, Bilthoven The Netherlands
      *To whom offprint requests should be sent.
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*To whom offprint requests should be sent.

Abstract

Investigations were performed to avoid cross-reactions in the enzyme linked immunosorbent assay, using the sandwich technique, for detection of Staphylococcus aureus enterotoxin type B. Non-specific reactions can be caused by cross-reacting antigens and by Protein A, produced by S. aureus. The former reactions can be prevented by adsorption with culture filtrate of non-toxin type B producing strains. The latter reaction is caused by the binding of Protein A to the Fc fragments of the IgG antibodies. Interference by Protein A was completely eliminated by using the F(ab')2 fragments of the IgG antibodies.

ELISA experiments in which these purified F(ab')2 fragments were used resulted in a highly specific detection of entertoxin type B, both in culture filtrates and in foods.

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