Figure 6.

Lysis of neuroblastoma tumor cell lines by human complement. Cells were sensitized to complement by preincubation with 8H9 and anti-IgG1 antibodies. Sensitized cells were then exposed to the indicated concentration of human serum (37°C/60 minutes), and cell lysis determined. Either the omission of sensitizing antibodies or the use of heat-inactivated human serum in cell lysis assays resulted in a background lysis <10% of test value. ▶ shows representative data from three separate experiments.