DEAD-box RNA helicases are important players in eukaryotic and bacterial RNA metabolism. A helicase from Staphylococcus aureus was recently shown to affect RNA decay, most likely via its interaction with the proposed Gram-positive degradosome. Some, but not all, RNAs are stabilized when the helicase CshA is mutated, and among the affected RNAs is the agrBDCA mRNA, which is responsible for quorum sensing in S. aureus. We describe how the stabilization of agr mRNA (and others) can be measured and how to conduct assays to measure the effects of quorum-sensing defects, such as biofilm formation and hemolysin production.