Stained Bacterial Antigens for Use in Microagglutination Procedures

We describe the preparation of tetrazolium-stained antigens from three significant bacterial fish pathogens — Aeromonas hydrophila, A. salmonicida, and enteric redmouth bacterium — for use in a microagglutination system. Serum titers revealed by the microagglutination test and the conventional tube agglutination test were practically identical. The principal advantages of the microagglutination procedure relate to conservation of time, space, and seologic reagents.