Immunomagnetic separation technique was developed for specific detection and selective isolation of Pseudomonas syringae pv. phaseolicola, the agent of halo-blight disease of beans. Whole-cell and exopolysaccharide fraction of the bacterium was used for polyclonal antibody production in rabbits. High specificity of the antisera was determined in agglutination reactions. The optimum immunocapture time for both antisera was determined as 1 h by using 1/nL CFU (i.e. 10(6) CFU per mL). No significant difference was observed in the binding capacity of cells to immunomagnetic particles with different antisera.