Confirmation of the existence of sRNAs by RT-PCR. Total RNA samples were prepared as described from cells taken from three time points of growth. The corresponding OD600 is indicated above each lane. RNA samples were used as templates for reverse transcription and amplification by PCR (see Materials and Methods) with specific forward and reverse primers (Supplemental Table S2), and the amplification products were subjected to agarose gel electrophoresis together with known size DNA markers (Fermentas). The sizes are indicated on the left side of each panel. (Top panel) RNA samples were checked for complete removal of genomic DNA, using primers specific to 4.5S RNA and tmRNA. When reverse transcriptase (RT) was omitted, no product could be detected. For each sRNA to be tested, a control was run with no template added (labeled -, on top of the lane). Each gel picture is labeled with the name of the tested sRNA.
