12th International Symposium on Bioluminescence & Chemiluminescence

Symposium abstracts:

Use of bioluminescence and fluorescence for the evaluation of affinity constants for bacterial cell-antibody interactions

Young, Denise¹, Griffiths, Mansel W.^1,2, Brovko, Luba^1,2

1. Dept of Food Science, University of Guelph, Guelph ON, Canada N1G 2W1

Email: deniseyo@uoguelph.ca

The sensitivity and time of bacterial pathogen enumeration can be improved by the use of initial separation and concentration of target organisms. Specific biosorbents such as immunomagnetic beads can serve this purpose, however, the efficiency of bacterial capture by biosorbents depends on the properties of the antibody as well as on environmental conditions such as pH, osmolarity, temperature, and water activity. This research focused on the use of immunomagnetic separation to determine the capturing efficiency of the immuno-biosorbent using constructed bioluminescent and fluorescent bacterial strains. The live bacterial cells used include bioluminescent-labeled E. coli O157:H7 and S. enteritidis, and fluorescent-labelled E. coli, S. enteritidis, and L. monocytogenes. The bioluminescence/fluorescence emitted from these cells were indicative of the number of cells bound to the antibodies such that Scatchard plot could then be used to determine the affinity constants. The affinity constant of commercially-available polyclonal antibodies was compared to that of monoclonal antibodies and the capturing efficiency was evaluated using varying environmental factors.

This is a preprint of an article accepted for publication in Luminescence: Copyright 2001 John
Wiley & Sons, Ltd (Wiley website)