FIG. 1.

RNA was extracted from concentrated raw (A) and treated (B) sewage by a conventional filter adsorption-elution method and ultrafiltration. Three different RNA extraction methods were compared, GITC-silica method (Boom), the NucliSens isolation kit (Non-magnetic), and the NucliSens magnetic extraction kit (Magnetic). Tenfold serial dilutions of the RNA samples were analyzed by RT-PCR and Southern blot hybridization. Poliovirus RNA was amplified as a positive control (Pos.C), and a previously amplified positive RNA was used as a blot control (BC).