Rifampicin-induced degradation of 23S and 16S rRNA in E. coli K12 and B strains. Total RNA extracted from equal volumes of culture was separated by agarose gel electrophoresis. In A, B, and D, the gels were imaged by SYBR Safe staining. M = DNA size markers. (A) RNA was extracted by cell lysis in TRIzol and purification with either a Zymo-Spin column kit or Phase-lock fractionation and precipitation with isopropanol. Lanes 1–3, RNA extraction immediately after the addition of rifampicin (biological replicates). Lanes 4–6, corresponding RNA extraction 30 min after the addition of rifampicin. (B) RNA was extracted by cell lysis in TRIzol and purification with a Zymo-Spin column kit. Lanes 1 and 2, RNA extraction immediately after the addition of rifampicin (biological replicates). Lanes 3 and 4, corresponding RNA extraction 30 min after the addition of rifampicin. In lane 4, ribosomes were added to the cell extract before purification. In lanes 5 and 6, RNA was isolated from purified ribosomes (-lysate). (C) Northern blot of RNA from B probed with 32P-oligonucleotide specific to 5S rRNA. (D) Rifampicin-induced rRNA degradation in BL21, W3110, and MG1655 strains of E. coli. Lanes 1 and 2, total RNA immediately after the addition of rifampicin (biological replicates). Lanes 3 and 4, corresponding RNA 30 min after the addition of rifampicin.
