T.Y. Barila D.G. Elliott 1987 <p><span>We developed a rapid method for detecting and quantifying the pathogen </span><i>Renibacterium salmoninarum</i><span> in coelomic fluid of spring chinook salmon (</span><i>Oncorhynchus tshawytscha</i><span>) by concentrating the bacteria on 0.2-μm polycarbonate filters and staining them with specific fluorescein-labeled antibody. Centrifugation of samples and resuspension of the sedimented material in phosphate-buffered saline containing Triton X-100 increased the ease of filtration. Background fluorescence was reduced by counterstaining filters with Eriochrome black T. Postfiltration staining, rinsing, and counterstaining were done in the syringe-mounted filter holders, reducing handling of the filters and possible loss of bacteria. The number of bacteria detected by the filtration – fluorescent antibody technique in a broth culture of </span><i>R</i><span>. </span><i>salmoninarum</i><span> ranged from 6.7 × 10</span>⁷<span>to7.6 × 10</span>⁷<span>/mL and was slightly higher than that determined by plate count (9.6 × 10</span>⁶<span>/mL). Increasing the sample dilution or decreasing the number of microscope fields examined generally increased the variability of filter counts of </span><i>R</i><span>. </span><i>salmoninarum</i><span>. Using the filtration – fluorescent antibody technique, we detected the bacterium in the coelomic fluid of 85% of spawning female spring chinook salmon sampled from a hatchery population.</span></p> application/pdf 10.1139/f87-027 en NRC Research Press Membrane filtration – Fluorescent antibody staining procedure for detecting and quantifying <i>Renibacterium salmoninarum</i> in coelomic fluid of Chinook Salmon (<i>Oncorhynchus tshawytscha</i>) article