+ Tom Kurtz, in a classic paper from 1972, showed that stochastic models for chemical reactions and deterministic models are related: in the limit of volume going to infinity, the stochastic model approaches the deterministic model.   

+ More recently, in 2010, Anderson, Craciun, and Kurtz showed that stochastic models for "complex-balanced" chemical reaction systems admit a product-form stationary distribution. This generalizes a result in queueing theory due to Kelly in 1979.

I will describe these two results.

REFERENCE : Continuous Time Markov Chain Models for Chemical Reaction Networks by David F. Anderson and Thomas G. Kurtz.