The present invention relates to methods for the detection of microorganisms. In one embodiment, the present invention provides methods for detecting live microorganisms in a culture by capturing and culting the microorganisms on para-tropic-coated paramagnetic beads. This technique is useful for any application in which it is necessary to monitor the biological contamination level, for example drinking water, recreational waters, food processing waters and medical laboratories. In one embodiment, the method for determining the concentration of viable microorganisms in a sample according to the invention further comprises an inducer reagent, wherein the inducer reagent includes an inducer compound that induces the activity of an enzyme unique to the microorganism of interest.