IMMUNOMAGNETIC BEADS AS A TOOL IN CONJUGATION EXPERIMENTS

We describe a novel technique for counter-selection of donor cells in conjugation experiments. The technique is based on application of antibody coated magnetic beads for removal of donor cells prior to plating. This makes the technique useful in conjugation experiments where no selective growth regimes can be applied. The technique was employed in conjugation experiments where a resistance plasmid, naturally occurring in the, fish pathogenic bacterium Aeromonas salmonicida, was transferred to Escherichia coli HB101 and a marine vibrio. Use of the immunomagnetic beads Co remove donor cells prior to plating resulted in transconjugants constituting 8.9% to 90.9% (Aeromonas salmonicida) of total plate count.