Activity and selectivity of SS2.

(A) Triplicate cultures of CD3⁺2B4 cells were incubated with various concentrations of SS2 for up to 72 hours. At 24-hour intervals, individual wells were sampled and aliquots stained with trypan blue and counted. Standard deviations of the mean for each data point did not exceed 29% of mean values. (B) Cells were cultured with monomeric ITs.