Cytotoxic activity of NetB (A168T) supernatants on LMH cells. The LMH cells were grown to 70% confluence in a 96 well tissue culture plate and culture supernatant added to the medium for 4 h at 37 °C. Cytotoxicity was measured by release of LDH from the the LMH cells using the CytoTox kit (Promega). (A) EHE-NE18; (B) EHE-NE7; (C) EHE-NE9; (D) 3 MB-2003; (E) 37; (F) 301001-1-B1. (1) Dialyzed culture supernatant; (2) culture supernatant pre-incubated with pre-immune serum for 1 h at 37 °C; (3) culture supernatant pre-incubated with rNetB anti-serum for 1 h at 37 °C. The values are averages of triplicate assays with error bars representing SD.