Ribonucleases remodel RNAs to render them functional or to send them on their way toward degradation. In our laboratory, we study these pathways in detail using a plethora of different techniques. These can range from the isolation of RNAs in various RNase mutants to determine their implication in maturation or decay pathways by Northern blot, to proving their direct roles in RNA cleavage reactions using purified enzymes and transcribed substrates in vitro. In this chapter, we provide in-depth protocols for the techniques we use daily in the laboratory to assay RNase activity in vivo, with detailed notes on how to get these methods to work optimally. This chapter complements Chapter 25 on assays of ribonuclease action in vitro.
Keywords: Bacterial cell cultures; Capillary transfer; Electrotransfer; Hybridization; Northern blot; Ribonuclease; Rifampicin kinetics.