title: RNA-Seq of ssrA mutant A. fischeri OMVs
design: A. fischeri cultures were grown at 28oC in LBS until late exponential phase (OD3). The cells were removed by low-speed centrifugation (8000  g) at 4oC, and the culture supernatant was filtered through a 0.22 m pore-size PVDF membrane filter (Millipore, Inc.). OMVs were then collected from the filtered supernatant by centrifugation. Purified OMVs were first treated with 4 mg of RNAseA (Promega) per ml for 10 min at 37oC to remove any surface contamination. The added RNase was then inhibited by the addition of 1 ul of Murine RNase inhibitor (NEB). The RNA within these treated OMVs was purified using a mirVana PARIS kit (Invitrogen), followed by DNAse I treatment (Thermo Fisher Scientific). The RNA concentration for each sample was then determined with a Qubit RNA BR assay kit (Invitrogen). Paired-end stranded RNA libraries were prepared (2x75 bp). Size selection of the library with inserts smaller than 300 nucleotides was performed before sequencing on an Illumina MySeq platform.