Stochastic Simulation of Biochemical Systems via Discrete-time Conversion

A discrete-time conversion is applied to the continuous-time Markov process that describes the dynamics of biochemically reacting systems within the discrete-state stochastic modeling approach (chemical master equation approach). This yields a stochastically identical discrete-time Markov chain and an according formulation of the chemical master equation. Simulating the resulting chain is equivalent to the well-known Gillespie algorithm but requires less effort. Thus, exactness as possessed by the Gillespie algorithm is preserved while the simulation can be performed more efficiently. Numerical examples are presented to compare the Gillespie algorithm and the discrete-time conversion approach.