Comparison of experimental and stochastic simulation results for percentage of plasma cell formation (A) and accumulated IgM secretion (B) under continuous LPS stimulation for 72 h. The simulated LPS dose response curves obtained at 72 h for percentage plasma cells (A, bottom panel) and IgM secretion (B, bottom panel) have an estimated Hill coefficient of 1.20 and 1.19, respectively. A simulated cell is counted as a plasma cell if the IgM level in the cell is above 200. The same standard was used for results shown in other figures. Accumulated IgM secretion data were normalized to the maximum value at 72 h for comparison. In vitro experimental results were from triplicate samples of primary mouse B cells for each LPS concentration, while simulation results were obtained from 104 stochastically simulated cells for each LPS concentration.