RT Journal
A1 Elf, Johan
A1 Ehrenberg, Måns
T1 Fast Evaluation of Fluctuations in Biochemical Networks With the Linear Noise Approximation
JF Genome Research 
JO Genome Research 
YR 2003 
FD November 01 
VO 13 
IS 11 
SP 2475 
OP 2484 
DO 10.1101/gr.1196503 
UL http://genome.cshlp.org/content/13/11/2475.abstract 
AB Biochemical networks in single cells can display large fluctuations in molecule numbers, making mesoscopic approaches necessary for correct system descriptions. We present a general method that allows rapid characterization of the stochastic properties of intracellular networks. The starting point is a macroscopic description that identifies the system's elementary reactions in terms of rate laws and stoichiometries. From this formulation follows directly the stationary solution of the linear noise approximation (LNA) of the Master equation for all the components in the network. The method complements bifurcation studies of the system's parameter dependence by providing estimates of sizes, correlations, and time scales of stochastic fluctuations. We describe how the LNA can give precise system descriptions also near macroscopic instabilities by suitable variable changes and elimination of fast variables.