Ribsowitches are putative drug targets as they often regulate the expression of essential bacterial genes. This finding necessitates the development of suitable assays, at best high-throughput (HT) compatible, which allow the screening of compound libraries for riboswitch activation. Here, we describe a HT-compatible fluorescence-based screening assay employing a minimal core motif of the Bacillus subtilis glmS riboswitch and the metabolite-induced self-cleavage assay using the full-length glmS ribozyme of Staphylococcus aureus for the identification of artificial molecules activating this regulatory RNA.