Before revision:  Here, we present and evaluate a rejection-free stochastic simulation method for determining the kinetics of multivalent biomolecular interactions . The method has a computational cost independent of reaction network size, and it is based on sampling a set of chemical transformation classes defined by formal rules that characterize the interactions in a system. We apply the method to simulate interactions of an m-valent ligand with an n-valent cell-surface receptor . Simulation results show that  the rejection-free method is more efficient over wide parameter ranges than a related method that relies on rejection sampling .
After revision:  Here, we present and evaluate a rejection-free stochastic simulation method for determining the kinetics of multivalent biomolecular interactions , and we apply the method to simulate interactions of an m-valent ligand with an n-valent cell-surface receptor . Simulation results show that the rejection-free method is more efficient over wide parameter ranges than a related method that relies on rejection sampling .