Abstract: A rapid method for the detection, identification and enumeration of specific respiring microorganisms. The method includes steps of a) passing a microbial sample through a collecting device to capture the cells; b) adding to the collecting device a fluorochrome dye specific for the detection of respiring cells and allowing the dye to incubate; c) treating the collecting device with a reactive fluorescent antibody which reacts with a target microorganism of interest present in said microbial sample; d) mounting the collecting device for examination by fluorescence microscopy in which a suitable light system is used to excite the fluorochrome dye and fluorescent antibody to fluoresce; and e) quantifying the respiring cells. Alternative embodiments include the use of immunomagnetic beads and other means of cell capture, and employing fluorescent oligonucleotide probes rather than fluorescent antibodies.