For the identification of RNA in RNA–toxin (fraction Nos. 18;31 in Fig. 1A), RNA was hybridized to C.botulinum DNA digested with restriction enzymes (as shown under Materials and Methods). The DNA of botulinum type E were digested by EcoRI, EcoRV,HindIII, or PstI and then were run in 0.8% agarose gel electrophoresis and transferred to nylon-paper sheets.